Blaze of Steel: Explosive Chemistry - with Andrew Szydlo

[Music] very good evening very very good evening ladies and gentlemen a very good evening to dear children in my hands Here I am holding an object an object which is made out of something which is very very common on our planet however it does not belong to this planet you see what I'm holding is a piece of an iron meteorite this iron meteorite fell in Mexico ten thousand years ago and it was it weighs three tons and a part of it was donated this part was donated to the Royal Institution in 1794 and I'm very pleased to be able to show you this now meteorites are made of iron and we are aware of the fact that people have been using iron meetcha Witek iron for about at least ten thousand years that's how far our records go however people have been using iron which they have been making by themselves for approximately five thousand years now if you don't mind I've got to give my meteorite away because it's very very precious indeed and I will come back to that later on now what I wanted to tell you is that iron is something which we associate with permanence it's something which is long-lasting that meteorite is millions and millions of years old the meat right there that that's lying so that's in in Mexico that's well there are thousands of meteorites the Mesopotamians the knew about meteorites they use and we know that people used meteoritic iron well before they started using iron which they made themselves iron is associated with permanence you go outside that you see you see lampposts you see bridges you see Hammersmith bridge beautifully made out of iron steel you see the Eiffel Tower made out of Steel you see railings you see road signs everywhere it is associated with permanence and perhaps I want to tell you that the greatest that the most famous or monument which exists in the world today of ancient iron crafts made by humans is the iron pillar in Delhi there it is the iron pillar in Delhi which is in North India has been crafted by people two thousand three hundred years ago it's a very very pure sample of iron and it is a mystery it is a mystery which I'll talk about that this has survived for so long in view of what I'm about to tell you so I am then his affair is associated with permanence with a long long jetty with a long lasting this however I'm there to demonstrate you in the next hour or so that any nothing could be further from the truth than the permanence of iron if it is subjected to the right sort of conditions you see I have here two sheets of Steel I bought these as an off cuts from a metal supply a few weeks ago and this sheet of steel as you see is nice and shiny as you would expect it to be but this sheet of steel here has got a sort of something which you are very familiar with you say yes it's gone rusty it's gone rusty it's beginning to corrode and this is not only not looking very nice but it is actually going to fall apart over a period of time now the reason why this one has gone rusty and this one hasn't because I actually left this out of doors I let the rain shall fall on it I left it in in awkward conditions and that's why it has gone like that now what I wanted to tell you about today is a little bit more about what rusting is and with that aim in mind I'm going to set up an experiment for you which takes quite a little time to occur I'm going to take a piece of iron comes by the way in all sorts of shapes and sizes and I would also like to tell you there is a very important distinction between iron and steel the distinction actually is a very small one I've got in here I've got a piece of iron you see which is very very pure iron it's nine 9.95 percent cure this is absolutely pure ID and I just wanted to show you how it comes its supply to laboratories and it's coming this a very special piece of paper like this and then in special waxed paper like this and you're really not supposed to touch it with your fingers you see there it is now that Pisa find their children cost 25 pounds that's how much it cost very very pure iron now the reason why it cost 25 pounds it's not because iron is rare it's because it is very very difficult and expensive to purify iron and when we use iron on an everyday basis it is actually part of an alloy which we call steel and steel is really what we have always used in our construction in all the sorts of things that we make on an everyday basis so from that one when I use the word I and I'm technically talking about steel this here is very very pure iron it is hugely expensive and it is really only used for special experiments involving chemistry what I wanted to do though is to show you an experiment and and to demonstrate what actually happens when iron and goes rusty iron by the way is supplied in many shapes and sizes and forms and I have here this is commercially available it's called steel wool and it's used for cleaning if you have a dirty surface and you want to clean it this is exceptionally good it's the same sort of stuff that brillo pads and pads are made out so for cleaning dishes what to do I'm going to and cut a piece of this it's interesting that I'm using scissors made of steel to cut the same stuff but I'll tell you more about that later on what I think to do now is to place some iron stick my steel wool inside my flask here and I'm going to push it in this takes a little bit of an effort by the way to make it fit in and then I'm going to make its go rusty I'm going to make it go rusty there it is and the way I'm going to make it go rust it's obviously by adding some water to it so I've got some water here which I'm just pouring in by the way I have to admit in all fairness that the water has had a little bit of salt added to it it's sea water technically and what I'm going to do now I'm going shake it up very very thoroughly in my floor so if you don't mind this is just to make sure that the piece of steel wool is getting thoroughly soaked now the only other ingredient in this class is air of course because the flask is full of air air is all around this I have now shaken up my my flask here maybe I'll add a bit more to you must excuse me I've got a supply of water here this is just to make sure that we give it a thorough soaking so we're just going to tell me out soak it like that and now we're going to turn it upside down to just let all the water drain out so if it's here for just a few minutes like that you see takes a little while for the water to drain out and then very shortly after that's I'll come back what I and what when iron goes rusty actually it combines with oxygen that's what chemists have discovered and when it combines with oxygen it changes its color to that orange form and I've actually got some powdered rust here it's a light brown color there this is now draining out I said I'll come back to it in about five minutes or so that's what I wanted to tell you is that when iron combines with oxygen that can also be interpreted as a process of burning because when things burn they combine with oxygen now you see if I took a nail I've got to nail here nice Oh shall we set the nail on fire I can put it into the cab so that's a stupid thing to do because obviously a nail and iron nail cants catch fire so there I'm putting it in of course and there is it's getting a bit charred on the end but that's just so no chance it's catching fire however allow me to show you some cowl that I've got some iron here in the form of a pearl then I'm just sprinkle that it's not a huge amount there's nothing spectacular but look at those tiny little sparkles it's a copy of see now that you see those tiny sparks there they're actually the iron is actually amazingly catching five seats made a few little sparks there and we can see that's there therefore that's very interesting where you say okay lots of things can spark up but let me show you another experiment with a piece of steel wool here and if you don't mind for this as I'm going to just put a pair of gloves on and also get my tongue so please excuse me and I'll just see what happens when we place a piece of steel wool in our candle flame so I need to take some precautions here you must excuse me and then we shall I'll come to the front so that you can see it better now as you know we do have a lot of things here and I'll just kick this balloon out of the way and I just wanted to show the surprising effect you see of putting up this is a gate line the same stuff that the the nail was made of were we just put it on a candle flame and they say okay that's nothing special it's glowing but actually if we start waving it around you see you see it starts to go even better and so what this is very pretty you see and you say wow isn't that amazing now what's actually happening there children the iron because it's in the form because it's in the form of a steel wool it has a very large surface area and therefore it is reacting with the oxygen this is generating a huge amount of heat by the way it's actually very hot so what we've done was we're combining the iron with the oxygen in the air and it is actually visibly burning now this is a very different type of flame from the flame which you get when you burn a candle or you burn a piece of wood and the reason being is that the product of this combustion process here is actually not a gas as most combustible things produce are gases it is actually a solid we are actually converting the iron here to the oxide of iron which is a solid and it is a characteristic of all metals when they burn if that's an appropriate term to use that they actually that they actually make a solid oxide if you don't mind I'm just squeezing the oxygen out of that to make sure it doesn't continue burning and very shortly we'll have a little sweeping session to tidy up if you don't mind I'm going to put this into the bin now for my next demonstration I'm going to set fire to a much a much more robust piece of iron and that is a piece of the steel tubing allow me to show you what the steel tubing actually looks like this this is a piece of mild steel tubing you see which I also bought and you know that if I put that in the flame that's not going to catch fire under any circumstances because this has a very large bulk and I'll allow me to explain to you the reason why the wool caught fire and why the power of the caught fire the reason is to do with surface area you see where things are powdered they have a very very large surface area so therefore the flame can easily access it and get the combination with oxygen to occur but what you have a large chunk of iron or a nail then the surface area is very slow very very small and therefore that same process with the with the the candle will not give you a desired effect however what I'm going to do now is I'm going to actually set this on fire I'm going to cause it to burn by a very different type of technique I'm not going to apply a flame to it I'm going to actually apply friction to it now you see friction if some if you rub your hands together you can feel them getting warm my hands are definitely warming up and if you can rub them hard enough then you'll feel them getting warm now what I wanted to tell you is I have a special machine here this is a tool which is used in by in industry etc and it's called an angle grinder and what it consists of is a motor which is connected to a disc you see this this care is made of an abrasive material and it spins around amazingly fast allow me to switch it on I have to warn you this does make a noise we call an angle grinder and when that wheel spins around it spins around so so fast that the friction it generates is enough to melt through the steel and also to set it on fire which is what I'm going to do next now for this purpose I'm going to introduce Demong cost can you both come forward and demonicus and modulate our two pupils from Highgate School in North London and they've actually they've actually been helped me to prepare the talk today and they'll be taking part in many many of the experiments so the Hmong cause this is if you could kindly put on now you must adjust we're always going to be putting on various safety gear because some of these experiments are actually quite dangerous so I'm just going to put on my goggles here normal put his on and we go what we're going to do is I'm going to sit fire I'm going to grind through that piece of mild steel and he's going to catch the bits that come off you see the dust that comes off and we'll examine it's very shortly so I'm going to first of all just do a trial run I do warn you this makes a lot of Sparks and it's incredibly noisy but I think we must observe these things in action so sue because I just think to go to trial first to see whether faster is that okay zon diatoms nowadays she collects a spark hold it in such a way that people can't see that's very good are you ready [Music] okay Don thank you very much so we now we now have to show you see we've done something which no builders or no engineers would ever bother doing we've actually collected the sparks the object was not to cut through the iron but to see what it makes where it burns you see and there it is there is that little bit of powder there now that you see what's interesting is that power which I've produced there has a black color it's a combined clearly with oxygen and yet it's got a black hell it's not brown like rust and I will very shortly explain that in the meantime in the meantime we have drained we have drained out our water from there I hope we've drained it out and what I'm not going to connect this up to a tube here and I'm going to invert it in a beaker full of coloured water and I very much hope that we'll be able to observe the rusting process now the children rusting takes a long time it doesn't happen instantly and etc so I'm attempting to show you a reaction which normally takes several weeks out in the open but I'm attempting to show you just a hint it'll be maybe it'll take half an hour what's going to happen is this as the oxygen it was reacting with our steel wool in there which has got water on it gradually the oxygen will get used up and it will create a partial vacuum in there so the air pressure will hopefully will push down upon hour upon hour the water the colored water which I've got there and hopefully you'll see it rising up the tube but this will take up to half an hour so we'll leave it standing there and I do believe that we're just off the mark on that allow me now Dom could we please take this away and take that lot away thank you very very much indeed and I will proceed on to the next demonstration which consists of showing you a more iron burning obviously since we're on this theme and I want just to show you first of all that some iron can be used in pyrotechnic that this idea of sparkling I think you for those sparks were rather good fun and of course used in commercial sparklers now I have two sparkless here and I'm going to ask DOM and and Marjolaine to burn one each this is just to show you you know they're they're fun they they just make that could you both please just light a sparkler each in the candle flame and just hold it you've all seen this before and what's interesting about sparklers is that actually they do you don't have to wear safety spectacles if you don't play with these at parties you see so there are just two sparklers burning like that now while those sparklers are burning I wanted to show you another application for a pirate so that's just you see sparkler that contains iron filings in it and it's burning away and it's very pretty and it's safe and all the rest of it and indeed what's also interesting you'll notice the sparks don't actually burn your fingers they're holding them and the reason is that the all of the thermal energy is consumed during the actual burning process they're very very tiny indeed the amount of heat energy is so small that it doesn't actually affect you I just wanted to show you now just a couple of other interesting demonstrations and usually this is purely for as a pyrotechnic effect and I want to show first of all a very small sample of gunpowder burning you see I have some gunpowder in here this is black powder and I wanted to show you how black powder burns just on its own without any additive you see that there's a there's quite a decent charge there's about 5 grams there and then you'll see you'll see how this is young powder burning on its own I've just got to double check by the way that I do have my yep that we do have the other one actually my my goggles are steaming up I'm so nervous I I think I'll just carry on I'm sure they'll be fine I do have either about 15 pairs of goggles by the way one for every experiment so there we are we'll put this one on now please watch carefully watch carefully as we demonstrate some stand that the black powder burning this is normal gunpowder and and they were a nice little puff of smoke going up into the atmosphere etc but please allow me you see chemists and pyrotechnicians always interested in improving things you see so what they said what some people somewhere they they noted these irons sparks burning etc notice the water is beginning to creep up by the way they noticed the sparks burning and they thought let's try adding some iron filings to gunpowder and let's see what effect that makes so that's what I'm going to show you next now I have to take great care by the way because these things do get scram they sort of the go all over the place sometimes the spot this is now gunpowder but mixed with iron filings once again it's a fairly small charge but it does have an amazingly pretty effect and I'm going to just set this on fire and watch keV so watch kept he was what you get is a beautiful shower of orange sparks in addition and it's also slowed down in its process of burning so this is now done powder with added iron filings or should I Sian pal der to make it it was a pyrotechnic effect and they've seen there was a whole little shower of orange sparks which came out and you see they've burnt little holes in the thing but that doesn't matter that's part of the demonstration we do expect to get through quite a few bits of paper and all sorts of other things so what it demonstrated for you now you see I've demonstrated for you a variety of applications in which an iron is turned into into iron oxide and I want it just to show I've actually got three different samples here of iron oxide already this one is rust that's powdered rust I got a rusty sheet and I scrape the rust off and I Pat that sound it's a light brown color this here this rust this oxide here is actually called pharaoh so ferric oxide it's tri iron tetroxide the chemical formula is fe3o4 three atoms of oxygen combined of three atoms of iron combined with four atoms of oxygen the formula by the way for rust is fe 2 o 3 dot h2o it's bit of it's iron oxide fe2o3 combined with approximately one molecule of water indeed if you heat this very strongly you will end up with this this is Cal signed iron oxide iron oxide which has had the rust which has had the water removed and formula is fe2o3 I wanted to tell you that these are relatively stable and we can examine them but there exists yet another type of iron oxide which no one ever sees but we're going to see it today for a very very brief space short space a period of time now allow me to tell you what I've got here is iron carbonate chemical formula F e co 3 now when you heat this very strongly as Dom is going to do maybe a season that flames strong enough Don we've practiced it a few times quite a strong turn it decomposes into FeO and co2 what's more they're unusual about this an iron carbonate it comes in I think it's mixed in with a tiny bits of sugar so it makes a sugary smell I'm not quite sure why that is but um can I leave you to it because I know you've done this before and in the meantime I will I will be explaining a few other little bits and pieces don't while you're doing that and make it what I'm going to tell me to tell you what he's going to do and then we'll relate it to a little theory I am when the iron carbonate is heated it decomposes to make iron to oxide Fe o let me remind you of the 4-minute this was epic 2 O 3 Fe 3 o 4 Fe 2 O 3 dot h2o but when this is made its chemical formulas f e o it is a very unusual and unstable type of iron oxide we call it pyrophoric iron oxide and what that means is that if you pour it into the air it's spontaneously catches fire and sparkles to make an iron oxide fe2o3 pyrophoric meaning it's catches fire carry on heating that until you already don't dope in ER but may we please have the next slide because I wanted to explain a little bit about this curious feature of iron and it's chemistry the reason why iron demonstrates this curious ability to link up with different atoms in different ways different elements in different ways now there in front of us is the greatest achievement of the human race in terms of our understanding of the nature of matter this is a periodic table of the chemical elements which I'm sure you all recognize and what it contains is all the building bricks of every single substance this is a remarkable achievement of us human beings that we've been able to organize all of these in Nice rows and columns now if he by the way is the Latin for iron Ferrum before chemistry we had alchemy and alchemists use the Latin tongue and many of their words still occur in today's language so there is iron in the middle and you notice it's in the middle of a large group of elements and which are all colored in yellow now those elements they're children are called the transition elements they're called the transition elements because broadly speaking elements are divided into two categories metals and nonmetals all the green yellow the green yellow purple and blue ones are the metals and the white ones at the bottom but just the top right-hand corner with the white ones in the column on the right those are the nonmetal that's a very very approximate division now I'm being a member of the transition metals what they specialize in is doing all sorts of chemical undertaking chemical rep they're all metals engineering metals but they undertake of wide variety of chemical reactions I'll quickly summarize them so it's a boy with theater but they have variable valency in other words they can combine in a variety of ways with one element variable oxidation state where they form colored compounds they form complex ions and they act as very good catalyst I'm going to show some of each of those in the meantime so can we have that slide off now please in the meantime I'm going to DOM we'll get ready to do that I am going to start off an experiment here you carry on dear Darwin are you ready by the way if it's possible if it's possible to turn the lights off while Dom does this and he's got a little watch glass on the bottom you'll notice if you dim the lights then I think you'll find this very very much more instructive and enjoyable to watch this so Dom you carry on at your leisure sir and there you see that you see is iron oxide FeO being spontaneously oxidized into fe2o3 thank you very much indeed their job now could we could we could we kindly now I'm setting up another experiment up here which involves the use of iron nails and what I wanted to tell you because this is next topic iMovie will so we'll have a look at the remnants in that glass in a second we'll have a look at the remnants in the glass in a second but I just wanted to tell you I am about to do an experiment I had a piece of cotton wool here which seems to have mysteriously disappeared it's not the end of the world if I can't see it but if but if I find it I will find it there somewhere oh there it is thank you so much ah thank you so much my dears this is Matt right here we got now what I've done in here I have in here I have in here some some nails this is harmful of iron nails and what I've done I have pulled about 250 mils of dilute sulfuric acid but I'm going to be generating hydrogen gas from this which will fill this balloon in due course it takes about half an hour I may have put too much acid in the thing is we have to move on now what I'm going to do now is I'm going to show some reactions involving iron and among those is once in which hydrogen is produced now this has a very important story the gas hydrogen has been was officially discovered in 1770 by Henry Cavendish 1777 and Henry Cavendish recognized it and identified it as an element but the honest truth is people have been preparing hydrogen gas since the medieval times they they reacted it by mixing this substance here which was then called oil of vitriol it was made by burning sulfur and sulfur iasts tombs were produced from various minerals and dissolving the fumes in water and they reacted it with with iron and they found that if you react oil of vitriol with iron then the iron starts to bubble away there and the wig which I'll spare to let it cook let the first few bubbles escape and we're going to allow this to a carry on bubbling now very shortly hydrogen gas will be produced I had iron powder in there and I had iron nails in here they are both reacting with the same substance sulfuric acid now this particular reaction had a huge significance in the year 1783 as you all know in 1783 was a great great date in the history of flight because that was the first time that man successfully launches balloons with humans in them and flew into the sky and there were two types of balloon there were hot-air balloons which were made by they and used by the Montgolfier brothers in Paris but times were very competitive and another Frenchman Jacques Charles made a balloon filled with hydrogen now these balloons were ginormous they were almost the size of this auditorium here they required tons of iron nails and sulfuric acid it was done on a huge industrial scale and when these balloons were launched they caused a huge sensation among the public so what I'm going to do is to actually use their technology using iron nails and sulfuric acid to fill this balloon with hydrogen now it takes approximately half an hour to fill so it grows very slowly this one by the way notice how purple liquid is rising up the tube and what that is showing is that the iron wool is going rust in there it is absorbing a vital part of the atmosphere which we know is oxygen but you see these are very easy to demonstrate today it took thousands of years it was Lavoisier was the first boy was a French chemist again at the same time as the Montgolfier brothers there was a huge amount of exciting chemistry going on there and he was the person who recognized that ayat that oxides of metals were solid and he was able to prove this now can I ask you and Dom and maybe modulate to burn off a few of those jars of hydrogen a few of the and the object by the way this experiment dear children this is what the point I'm trying to make the object is not to make hydrogen it's to make what's going to be in that flask the object is to see what the iron turns into but if hydrogen is being produced we must not waste it and therefore we shall burn it and so that will be the site that will be this please feel free to burn off as many jars of hydrogen as you like if we're provided it comes off and in the meantime I will concentrate on our next experiment so you feel that one probably won't have any hydrogen it by the way they have not practiced this at all so this is just doing things from first principles but I think I'm I'm have every confidence the first one they will be full of yeah that was pretty pure hydrogen can I by the way while I'm demonstrating I'll just show them a few tricks then they can end happens more can I show you a few tricks please dome and modulate right but first thing is this that a good idea would be where you keep that burning that's very handy if you actually mix it with air okay then it will make a slight pop you see there you are far more fun I see so I just want to do two while I'm doing that you pin and you can enjoy this and put a lid on you see like that so the point is for pure hydrogen pure hydrogen burns with so when you when you actually do the experiment well it's about 50% about half full will make a pop if it's any more than that then it will decreasing the until one which is pure hydrogen one you first but that was absolutely that makes virtually no sound is what please I want you to carry on now the reason why they're carrying on because I am now going to do the next experiment here now I'll repeat once again the object of this experiment is not to make the hydrogen it's to make what's going to be in there and I will tell you straight away it's iron sulfate feso4 otherwise known as green vitriol and if you look carefully around you'll see some standing around on the bench but what I'm going to do here at the back here is a much more tricky you must carry on regardless and I'll ask you to from one moment to break the demonstration there and when we will and then I will tell everyone what's good to concentrate when you carry on for a little bit now what I wanted to tell you here I've got some iron nails I hope you could all see them in this flask let me just hold up some iron nails in there and I'm going to make iron a different type of iron in this flask this is going to be what we call iron to Fe 2 plus pale green as it will be but this one here will be iron three-plus which is dark brown now Dom can we just let's just take us a short break this is purely so we can all focus on we can let that bubble over and you can return to that in just a second and I'm going to now demonstrate for you what is a reaction in which we which is I'm hoping works out to be good fun because I'm going to prepare these two these two flasks this one will hold our green solution being made pale green solution being made in there and this flask here will hold hopefully a dark brown solution which is iron three-plus so two different oxidation states of iron typical transition metal chemistry you know this one reacted with sulfuric acid but this one we are going to react with a strong solution of nitric acid it's a very it's a relevant relatively concentrated solution and for this purpose I will of course be wearing safety spectacles now I did actually put some I had some less less of the sort of we got those coral your ones my dear I've got about six pairs of these thank you very much indeed because we don't actually the heavy-duty ones and this now what I've got here is concentrated nitric acid and in this experiment we react a solution of 50% nitric now nitric acid is a powerful oxidizing agent by the way so we've got so what it does is it oxidizes Fe to Fe 3 plus which is ready I'm adding water to it to dilute it down to to dilute it down to about 50% strength and what I'm and when this happens this is rather quite dramatic which is why I've canceled everything over there in order that you can watch what goes on here we can put this to one side and that will be taken away and this too will be taken away in due course is that's okay though let's watch this first though because I hope this this the user now allow me to tell you what happens when iron reacts with concentrated nitric or percent nitric acid it releases a huge amount of a dark-brown gas nitrogen dioxide and it also gets very hot indeed it's what we call an exothermic reaction that might in dioxide is also very poisonous so we mustn't allow it to escape so what I've got here is what we call a scrubber this it's technically that's the engineering term this scrubs out the acid gas nitrogen dioxide it's actually water almost pure water with a true few drops of universal indicator and a couple of drops of ammonia to give it the alkaline color this here is a flask which has got just a few drops of strong ammonia solution and this one here is a flask with ammonia solution in it diluted with water now the purpose of all of this is to absorb our dangerous toxic nitrogen dioxide gas and neutralize it but there is a second purpose when right the amount this here is a tiny tiny amount of solution which would when it gets hot half of this will evaporate away and disappear so what I've done in this experiment is going to do is a physical effect as well once the chemistry is over this will be very hot indeed the I will then call this flask down by pouring water over it and hopefully as it cools down it will contract and all of that water will get sucked through into there and dilute our solution to make a flask half-full of a beautiful brown liquid now this one in the meantime is getting slightly over the top dome if we could just monitor that on an occasional basis they heat up and they froth up and at a certain stage long you'll be able to disconnect it okay just swirl it around every so often but I think we should all try and watch this now and I hope it worked if it a swirl around them and let's go this one by the way all happens in a space of three minutes so I'm just double-checking that all my joints are tight and you're going to see quite a lot going on in this reaction so there goes our nitric acid in there initially nothing happens so with a small space of time you see you see very very vigorous bubbling so there's how brown fumes of us and now what's the color here / all green and now gone to red so we now have red it's the gone acidic we have white fumes here of ammonium nitrate which is relatively harmless but you notice there's not a single smidgen of our dark brown acidic gas so this experiment is totally safe this is ammonium nitrate with a bit of ammonia added in which is perfectly satisfactory at these levels in the meantime Dom has cooled down our flask which is reacting can I just show it to everyone though it's frothing up it's frothing up and the way we call it down down we simply add water to dilute okay so I'm just going to dilute the reaction down and you say but low you said it's going to be a nice green color I can't see any green color there at all it's a murky black color of course it is but you see that murky black is due to the excess of iron filings what I'm now going to do is to pour it through a filter paper now the filter paper should hopefully filter out the solid particles and with a bit of luck we should get a beautiful pale green solution of iron ii sulfate now I'll leave that running on the front here we'll leave that filtering and gone I may ask your modulate to add some more once the level has gone low in the meantime let us examine our reaction here the reaction has now almost finished its wait so that all the acid will swirl it around a little bit whoof that is very hot indeed probably about 45 to 50 degrees centigrade that's very hot indeed and you will notice that the fumes have stopped coming out this is we where we start the fun with the pneumatics we're now going to conduct a physical effect I'm going to cool this down and as I call it down you'll notice it will hopefully suck back water from there there we go it's now sucking water back from there because this is cooled down and the gas is very soluble in water we're sucking the ammonia is going back through to here and we now have a flask which is got a significant amount of a very beautiful dark brown iron three nitrate so in this flask here we have now in its stages of filter you could begin to see the beautiful green color becoming apparent there and here we have a flask which is pretty brown in color and that is now contains iron three-plus now you'd think you would think that this is now totally safe that I have got rid of all my nitrogen dioxide which is deadly poison but actually please watch carefully because when I take this off you will notice suddenly the appearance of the dark brown poisonous nitrogen dioxide please watch carefully and there it is you can see the fumes coming off there and if you thought that was the overly flask with it in then there it is can you see and it's continuing to suck more water now German theater the reason why this has happened because actually in this experiment there are two gases produced one of them is nitrogen dioxide no2 and the other one is nitrogen monoxide n.o and nitrogen monoxide which is here there and there has no color whatsoever it's a colorless gas but it's unstable and it immediately reacts with oxygen to make nitrogen dioxide a little bit similar to what you saw with Fe O going to Fe 2 O 3 the same sort of thing so if I disconnect that then we'll get them get the 2 litre could you see there the brown fumes but I'm not going to pursue on this thank you very much and indeed and what I'm going to do now I'm with the over the object was to make our Brown solution and I shall now replace this flask here and I will ask maybe a we can actually we could leave it here for the timing but we will later at this span this now here we have this murky solution you see here which is essentially iron 3 nitrate and when we filter this this should give you a very very beautiful brown color a dark brown color of iron well in what we call a different oxidation state so here you see out in these powders here here we have i/o we can have a look you see as the iron oxide fell to the ground it oxidized and it's gone dark red you see which is the color of this so that's fe2o3 which is there so that's our product which we've managed to collect down there so in the meantime our steel wool is rusting and the water is rising showing the consumption of oxygen in the meantime here we have now got two kinds of iron in solution this is iron two-plus and this is iron three-plus both made by reacting with acids but in this case with very different acids one using nitric acid which is a powerful oxidizing agent and is able to get that extra combining power the other one being sulfuric acid which merely achieves the fe 2 plus oxidation state now in the meantime our balloon is filling we're well on the way but we've still got about another 20 minutes and now I wanted to talk a little bit about the solutions that we have made I'm just going to find I need to find a couple of we need to be able to allow these to carry on dripping so that one can go back into that flask and we'll put this one back into this flask here so we've got our two specimens of solution and I just want to show you now a few chemical tests to distinguish between these two types of iron and for that purpose I've got four solutions here which are used commonly by analytical chemists to show the one type of iron from the other type of iron and I'm going to start off in each of these here I have some sodium hydroxide solution and what happens is with sodium hydroxide solution the two different types of iron make a different colored precipitate so one is iron so I'll just pour a few drops in from here and you should see a dark green gelatinous precipitate form there it is it's a sort of murky green gelatinous precipitate of iron two hydroxide this run will obviously make a brown precipitate of iron 3 hydroxide there it is and we call it a gelatinous precipitate looks like a sort of a geli that settle down on there now in the next one here I've got a solution of potassium ferrocyanide I can't remember which is which there are two solutions both pale yellow in color ones potassium ferrocyanide and the others potassium ferrocyanide but what they do they very nicely distinguish between the FE 2 plus and the fe 3 plus and you'll notice the color they're very dramatic color changes when the reaction happens so I'm going to put some Fe three-plus in here and we'll see whether that's the dramatic color and there it is a beautiful intensely deep this is called Prussian blue that there it is it's a very dark blue color there and we've got it there you see that's the Fe three-plus now with thee with this one here it shouldn't work but it does because the FE 3 plus is actually mixed in with a bit of Fe 2 plus so there you see we are getting the same thing here however if I take I don't have a my bottle with me but I'll explain a little bit more what we've got here that's your Fe 3 plus with a small amount of Fe 2 plus which that has shown to be the case however we now do this one here a few drops of here this is the other one you again getting fresh and blue in this case and intensely deep blue all no silly sugar I should have done this one as I should have added Fe 2 plus Oh Deary Deary me let's have a look that that's the FE and I've messed this what don't could you do me a favor run to the department and get both a ferrocyanide and the fairy sign light because I've muffed it up please excuse me one makes mistakes when one is in a hurry and I'm in a hurry now I wanted the next one here the next one I got thiocyanate and fire sign eighths is a very spectacular way because this one distinguishes this one you only need one or two drops of Fe Fe three-plus and it shows you a brilliant dark red color so please just let's just watch this in C we can get this there we are this is intense dark red color this is by the way what we call complex ions thank you very much Tom if we can basically I'll tell you what if you just get rid of those two down in the bucket and we'll put some fairy cyanide back it will repeat that extra so that thank you very much indeed so there is there is Fe Fe three-plus in there and if we put the FE that that dark red if we put some in here and if we put Fe 2 plus this isn't me getting confused Fe 2 plus it should have no effect at all on this you see shouldn't produce any of that red color so there it is you see I'm adding Fe 2 plus there and it has no so this is a very definitive test for the iron 3 ion this intense have we got those two beakers there again thank you very are they they're messy doesn't matter we'll rinse them out we have everything on hand my dear boy look I've got me I knew the annuities I'm prepared I'm hopefully I'm prepared for all sorts of situations thank you very much indeed one of these clearly was just rinse those down into our bucket waste bucket thank you very much Tom we'll just quickly have a go and see why to get this one - this is ferry cyanide which works with which should turn an intense deep blue with fair Russ with ferrous so we'll put the fair Fe 2 plus in there and well we'll just see what happens I think this one must always there must always be a spirit of enterprise and business going into the unknown there we are we have an intense blue what's happens with what happens in here don't bother ok let's try the other one rich this 1 hour later I getting myself confused you know with ferry and Pharaoh it's them no no this is very confusing will now try the same with these to let a little bit more water Dom you're becoming a master of the secrets now allow me to oh by the way while we're on that subject I have another beautiful experiment for you a beautiful explode weekend I'm going to grow you some plants now some plants made out of iron two-plus and iron three-plus I have it here I have been a substance which is called water glass it's actually a chemical and we can make chemical Gardens with this and this is probably the most beautiful experiment you're going to see today with just giving another little rinse out Dom I've totally forgotten what I was doing there but I'm sure we'll get there eventually now I'm just going to what I wanted to tell you is what this does by the way these also these are beautiful crystals of iron sulfate which I've grown for the past few they I think they're so beautiful I just wanted to show them to you and that's what's actually being made in there's the if you allow this solution here to crystallize that those the crystals it makes but if we pop some these crystals in here a small quantity by the way they totally harm a couple of these crystals in there and a couple of smaller ones because those are large ones whoops-a-daisy so I'm getting my lids confused yeah let's just go there and a few small ones down here a few smaller ones here this is iron ii sulfate but in a larger sir it's got it's much smaller so larger surface it'll go happen and i'm now going to add to it some iron three chloride now I am free chloride will give you some hopefully some Brown plants and what will happen in the next in the next half hour you'll see a beautiful chemical garden made of iron and there'll be two kinds of iron Brown iron and green iron and children if you've even if you've forgotten all the chemistry just remember that iron has two colors green and brown and that will be very good enough you'll then say that you learnt a lot but this I've Airy much hope this will show you this demonstrate this in the most beautiful manner now in the meantime now what was I going to do dahm because I have forgotten sorry which one's going to be this one ferric ferrocyanide now yeah let's try I think one must always one must always I'm trying to get you one where what happens it goes a beautiful deep blue in one but a very very beautiful aquamarine in the other so this is our Fe 2 plus ah there it is I've got the result and here you see no that much I don't know the other one are you short no no no she wasn't meant to no no this is the one go dark blue doesn't it no no I'm sure this is right I know I am stupid he's right I'm a disaster there we are look I've got it now by hook or by crook I hope you've all understood as you see I don't but thank goodness I've got intelligent people enough gone thank you I'm stupid I should listen to my students thank you very much I'm so but though you think that's a beautiful blue that's another complex I have no idea what it is but it's beautiful I just wanted to show some nice colors I don't understand what I'm doing I can't even do it but we're getting a result now let's let's hope let's hope that I can show a little more intelligence and my dear Dom could we just love this lot into the bin now we've got to clear some space now let's have a you must excuse me little Thai the obsession now a little tidy up session can we just lob that all into the bin please Marjolaine and dom thank you so much you leave and put those to one side a little tidy up sighs now Oh could you see our beautiful garden going dear children I'm not going to disturb but look our iron is rusting and our balloon is grew so we are actually I will hold it up later I will hold the tablet and I promise you things aren't working we're getting more success than not success now let's put that away now as I was saying so we've got we've got the ferrocyanide in the ferry sigh now you saw color changes that was the important thing and they test it for something and I know in theory but in practice it's all look at this isn't it amazing it's sucking it's sucking this out because the oxygen as this is rusting in front of your own eyes it's sucking the water in to replace the oxygen which has been consumed and as it's turning to a solid now what I want to show you next is that it's a very beautiful reaction I told you that and the on the transition elements have these various characteristics I was going to throw this into the ask you to throw that into the yes if you could take that away they'll be fantastic and put that in the blue trade which is in the green room thank you very very much indeed now what I wanted to show you next which I'm hoping will be a successful experiment is a beautiful redox reaction it's a reaction which Fe 2 plus reacts with reacts with reacts with permanganate solution which has this beautiful dark purple color because it doesn't marry spill a little bit it has this beautiful dark purple color and let me excuse me I'm just this is warming up a little bit it's getting a little bit warm we need to cool it down but dormant soon cool that down for me and all will be restored because if it allows it gets it gets very hot and it Frost's up and it all goes into the balloon but we should be okay we're nearly ready for launch by the way we're nearly ready for launch now this one here what I'd um could you just control that and shove into a beak and put the beaker on top sort of people can see that's what we call quenching a reaction it's it's getting very hot indeed so it's not actually that hot yet but it will get it will be getting warmer and that will just prevent it hopefully from getting a bit too excited so will yeah we can gradually keep an eye on that dear Dom because we'll whip the balloon off if it looks dangerous I just to show this reaction here in which we've got some iron two-plus look just a tiny bit left in there and hopefully a couple of squidgy I'm short of glass rods I'm a bit short of Glide oh I'll use a thermometer we could use a thermometer to Stacy and there we are I wanted to show it this is a beautiful reacts called redox process in which we take Fe 2 plus and we add it to permanganate ions which are purple and you should get a very very spectacular color teacher this becomes converted to Fe 3 plus you see remember yellow-green blonde going to brown so here we go please watch I'm going to swirl and adjust a squirt in there and swirl it and see if any times nothing yet you see but that's take it does as I said this sure won't happen immediately there we are give it another swirl around there and we're getting there we're getting pale you see our redox process is taking place and then another squirt there and finally we're so close let's just lob the whole lot in dammit this has got to work oh there we are and they want now and you say hang around hang around should low you said it's going to go pale Brown because we've made Fe three-plus well the answer is we have made Fe three-plus but it's so dilute that we can only show its presence with a magic thiocyanate test now is it possible that I've got thiocyanate in there in that is that far do you think that might be 5 cyanate let's take a risk I'm taking a risk I've lost control but I'm hoping you see this doesn't look but if we score that maybe we'll get a dark ah ah so you see we've proven that we've made Fe three-plus you see so we've actually notice to say that so you see this doesn't appear to have Fe three-plus but this you see and this is chemical analysis chemists have developed fantastic techniques of of being able to detect tiny amounts of substances using very very very sensitive chemicals thank you very much that was oh thank god this we got that one now I wanted to show a next one the next one I have got to show now Tom are you keeping it sorry no it's not quite ready yet we're very nearly there Dom a few more I reckon that's got another another 10 minutes to go yet okay so keep it C Buchan it I think it's fine I think we're on the control we're not going to go over them now I wanted to introduce you next to a chemical reaction and which is which is another another characteristic of these transition elements because iron represents transition metal chemistry in the most excellent way as I've said that the idea they can form these two oxidation states fe 2 plus and fe 3 plus green and brown the fact that it can undergo redox reactions it can easily change from one to the other as I have just demonstrated there the fact now another important characteristic of transition limbs is their ability to act as a catalyst now that means it can speed up a chemical reaction now what I want to show you here I'm now going to pull out three flasks 3 3 M glass 3 bottles you see and in these three bottles I'm going to show a chemical reaction using these 3 bottles and I'll tell you exactly what I've got in them and I'm going to show you a chemical reaction which is very beautiful to look at but which we will then do in a controlled manner using iron two-plus as a catalyst by the way I've got some some sort of neat stuff here prepared iron 2 plus 1/9 repass I hope you can all see iron 3 or red I and Brad Brown iron and green I'm now what I wanted to show first of all is a chemical reaction which doesn't involve iron at all but it's a very very beautiful reaction and this is the reaction between potassium iodide solution and acidified peroxide it's a it's so I'm just a just pour just this just to show you what we are going to be demonstrating as a catalysis so there's the reaction itself there is a there's nothing's happened yet but if I add potassium iodide solution some acidified peroxide you should observe a beautiful golden color appearing which is iodine so a dilute solution of iodine and there it is you see so that there is a dilute solution of RT now it so happens that it's possible to reverse this reaction and go back from iodine which is brown to iodide by adding sodium thiosulfate solution now this is a fairly complicated redox reaction but you don't have to understand it's to enjoy I certainly don't understand it but I enjoy it so here we are I'm just pouring in and you'll notice a little bit and there it goes the color has Jessica and the color has gone however please watch as you leave it you'll notice that the color starts to come back again and it returns you see and this is a reversible reaction you see we're disturbing the equilibrium in chemical parlance now I think you'll all agree that the gold color is very beautiful but it's not exactly a sharp and strong color so what we can do we can intensify the color by adding an indicator in his face ditch starch and if we add some starch let you see we get a dark it's a dark blue color officially it certainly is dark and we can repeat the experiment by adding a little thiosulfate to it you see by adding a little fire sulfate and making the dark color disappear if I add enough hanger allergist see yes there we go now but if you watch it though you see at the certain moment suddenly the blue color will reappear a voila hey well ah now you see what I'm demonstrating what I'm demonstrating lady thermistor is merely a chemical reaction which can be made to go backwards or forwards depending on how much of the ingredients what proportions of ingredients now technically speaking or among chemical demonstrators it's called a clock reaction you see so what we're going to do and what I'm going to tell you is that iron sulfate you see iron two-plus actually catalyzes the clock reaction it can make it go faster so what we're going to do we go to make up two identical mixtures two identical mixtures containing iron containing 100 CC's if you can Dom if you can do a hundred cc's of thiosulfate into each beaker I will do a hundred CCS of iodide into the big beaker okay and maybe marginally if you can do a hundred C so we need 100 another measuring cylinder damn it will get wet in a second dear marginally we'll reach this out I can ask you to do that one there so a hundred CCS of its approximately don't have to worry about exact corner but we're doing this we're doing this to show you what's known as a fair test yes into each year 100 CC's there actually and then and then we got to do into the other ones I'm so nervous I might get this thing I've drawn up let's just quickly might get my wedding before oh well ah there we go there now marginally if you can quickly using that just pour in a hundred cc's of hydrogen peroxide into each of those thank you very much indeed one hundred cc's of hydrogen peroxide thank you very much indeed now what I'm going to do I'm now going to add some starch indicator yeah hundred cc's of each and that now so we add the starch indicator goes in here one squirt there and the starch indicator goes one squirt into here get it's reasonably close to us one hundred as you can it doesn't have B exactly but with in with thank you very much Andy that's one there and we're now going to have our iron thank you very much we're very close to it Dom but people you're doing very well indeed they're these two my guardian angels for tonight they they're wonderful thanks to them I'm surviving this evening right very good indeed thank you very much my dear modulate that's wonderful now what I'm going to do what I'm going to do I'm going to add a squirt of iron ii sulfate into one of them but not the obviously so just a few drops there just a little there that's it catalyst you do not require now catalyst as I say speed up the reaction so what I'm now going to do I'm going to add these the hydrogen peroxide together they but we you have all witnessed identical quantities being measured and we shall then put them up we shall stir them and then we shall observe to see which one this one should go faster because it's got the iron in she's so ready still you go there we are and they it takes it takes up to a minute see so there we have our two solutions they are right then can we take these away please we finished with those now we can put these may be up just keep them there and we'll see when they turn one of them that this one should turn blue first followed by that one oh there it is you see so there it is and this one so you see this is an example of catalysis in action so we've demonstrated that one my fault I will use catalysts are hugely important in the chemical industry the whole a huge amount of money spent on research into developing catalysts for chemical processes indeed most all modern cars now have catalytic converters in their exhaust pipes that's to remove harmful products you see this one's taking the devil of long but it will get there eventually now in the meantime our there it is Susi catalyzed uncatalyzed our thing is rising here thank you very much dear Dom that's coming on now in the meantime this balloon I think this is now ready to be launched with it it's actually doing incredibly well it's probably the best one we've ever done and it hasn't overcooked you if you could kindly carry those away that will be more than perfect and that one as well thank you so much so I'm now going to try this balloon off I'm going to detach this balloon I'm going to detach this balloon and and try it obviously this is a big challenge for me and we're going to it's full of the lightest gas in the universe which is hydrogen you see and as I said hydrogen caused a huge amount of excitement in the 1780s with balloons I'm just tying it off here I'm just tying it off Arella and now what we're going to do we're going to see how high it can go Marjorie you can have the fun launcher the size of three-quarters of the height up and then tie it off down there onto the weight is that's okay and I will in the mid so Dom if you could sort out the balloon I will in the meantime get on to the next experiment involved the iron by the way please notice how beautifully these chemical garden is growing you see now you see they're beautiful they're like literally live plants and you will be able to come and have a look at these later afterwards they're children now we've finished with these three bottles so I can put the three bottles down there I know to move on to something something completely different that you're not that completely different it's still chemistry but in fact and we're moving on into the field of alchemy there are the balloon is there wonderful wonderful anchor it down and we shall we shall not be wasting that oh I forgot one experiment by the way it's will may as well show you and that's how to burn steel wool in oxygen into oxygen there's no harm in doing an experience even if it's slightly out of context or late but I showed you steel wool burning it is by the way highly flammable as you saw one spark will cause it to burn and I have a gas jar here which has been filled with oxygen earlier on and I just wanted to show you how these steel wool burns in and burns in pure oxygen so which is gated and I've got gloves on because this is a very very brilliant flame by the way it was possible to dim the lights down then I think that ever and I'll trying to I feel you and this will should I'm one of the important things thank you so much brilliant brilliant the balloon is fantastic what we'll do is I will just show you and we'll just put this I'm going to punch and you'll see it should make a very very bright white light indeed and crackle away so there is the flame just alight and they see sparkling away in purity now that's molten iron dripping off there as it continues to burn molten iron iron oxide and the whole thing is glowing you see so this is into oxygen I'm pleased to tell you that Michael Faraday Houston lecture here in a one of the greatest science of all time did it you should do this exact experiment so it's at the time has not changed it's still important whether we learn you see and and the fact is that these the oxide there which is made is a solid in contrast to the oxides made here which are carbon dioxide and water vapor which are vaporizing up into the atmosphere so pure oxygen obviously is a supports combustion far better than air which contains 20% which is what we're demonstrating here which is what we're demonstrating here you see it continues to rise and the reason why it's rising is because the iron wall is reactive now I want it now to move to a slightly different experiment but we're still on the reactions the chemical reaction of iron and I have a bag of nails here I have a bag of nouns and I and I have a pair of scissors and I just wanted to pour the nail sports and nails into Haiti pour some nails into my container there I also wanted to pour some more nails here some different nails there and also stick this in here now what that lead to demonstrate for you is an experiment which has actually been known for many many hundreds of years but it's the interpretation which has company I'm pouring it onto a solution which we today call copper sulphate solution but for many many hundreds of years it was known as blue vitriol and I'm going to let it sit there for just a few minutes because I wanted to tell you that this sort of experiment which are about to see now was an experiment with which people have been familiar for many many hundreds of years and it's very very spectacular now the sort of people who used to conduct experiments hundreds of years ago were called the alchemist the alchemists were people who who believed in the idea of the four elements earth fire air and water they believed in ideas of transmutation that one element can change itself into a different element they didn't so much believe what they saw they believe what they had been told was very very important they believed in knowledge handed down from the ancients and for instance the legendary founder of the alchemical arts was Aramis Trismegistus Hara mr. thrice-great who wrote down an emerald tablet with 13 rules of how matter changes into different substances and the alchemists using those rules attempted to interpret all the observations they saw and furthermore they conducted their own program of experiments their program of experiments was very noble they wanted to make medicines which would cure you and make you live forever they wanted to find out the secrets of life and death how could you how are people born how does reproduction occur is it possible to get people or animals and plants that have died to come to life again experiments in palying Genesis the experiment to make the Philosopher's Stone the magic transmuting agent which could turn base metals into gold but not for the sake of becoming rich because the alchemists saw gold as the height of perfection it's a metal which never tarnished and they aspire to that they were all so profusely religious people they were deeply they were deeply in the spiritual and they used to pray profoundly hoping that their experiments would come to a success they use are the prayers like this Norman anon song dig in also in respect to mom said tantum DIC verbo it's an arbiter re mama that was prayer begging law to purify them in order that they could conduct their experiments and get better results now if I now decant for you our copper sulfate solution and show you what's left inside you will see the sort of effect that Wolfe there me you see I've poured it on a beaker which I didn't have enough volume for silly I'll never mind here we are this is the important thing you see what happened an apparent transmutation this experiment has been known for several hundreds of years and what they believed that they were achieving was they were actually transmuting a base metal into a more noble metal now Tom can we kindly ask you because the I've made the usual mess I've got they've got the wrong beaker I hadn't thought that well I'll just pour it up into this is now waste if you could kindly take those where I'm just going to mop up the mess I've made here thank you very much as most kind of you once again etc I'm just going to put all these things into the bin here we'll have a little tidy up and they will pour will tip our nails out and just have a quick look at them here thank you very much indeed and we should be able what we can pour we can pour the remnants of our solution back here and we can go here so so when these when these nails you see and when our sheet appeared to be turned into copper they believed that they were getting closer to their ideals they thought that they're on the way to success you see but what I wanted to tell you of course in modern chemistry this is of course a thin plating of copper that we've achieved here and what we've actually conducted is something which is known as a displacement reaction and we can explain this iron plus copper sulfate makes copper plus iron sulfate so we're back to making our green vitriol which we have in here you see in the form of beautiful crystals and I wanted to tell you that this is not only called the displacement reaction but it also has another type of name it is called redox reaction it's the same reaction just a different word for it what I wanted to show you now is this same reaction but done in a slightly different manner we'll be looking for something other than just the coating of copper I have here a large a large quantity of iron fining these are fine iron filings I've pulled them into there it's once again and I think you can all understand this reaction will happen quicker than that one there because this is powdered iron therefore it has a larger surface area so I'm going to pour in my copper sulfate solution once again and the reaction will be exactly the same iron plus copper sulfate makes copper plus iron sulfate let me just swirl this around swirl it around here now theater of the importance can you see it's going green we're going green we've actually almost we've got to the majority of shoes we're right with 40 50 now could you see there's a huge temperature rise huge temperature rise here and what's happening is here we've now the copper is at the bottom and you notice it's almost boiling now the important thing is this reaction is exothermic skidding off a huge amount of heat energy huge amount of heat energy and that is now registering 40 50 degree centigrade so here we have the same reaction you saw there but this type I'm monitoring an energy output now we can also get exactly the same reaction believe it or not if produce not only heat energy but it can also be made to produce electrical energy so what I'm going to do is set you up the same thing here I've voltmeter here and and show you the production of elec electrical energy here using our and our two substances iron sulfate and copper sulfate now if you could just get me some white a piece of that white tissue please and I'll make a quick salt bridge actually know where I put my potassium nitrate solution should be somewhere yeah that's it that'll do that loudly fine copper sulfate in here copper sulfate in here and we can actually get another type of energy which is electrical energy so we've had we've had heat energy produce and now electrical energy so I'll take a piece of this tissue here and we make a Seoul bridge by bathing it in potassium nitrate solution so if you don't mind this stuff's totally harm it's just gonna there and this is what it's an inert substances essentially making a very electric cell so we're just going to put this in here like that pull this in here like that we're going to connect our positive electrode there and please watch carefully when I connect to thee so there's one there and hopefully whoops-a-daisy bomb can you come and one of you just hold this for me um I tell you what if we just hold this put that one on there let's not hang out back to the audience if we can see these just Santa now it might be a few connect that to the iron electrode you should all see hopefully not 0.3 of a volt there you go and you see so what we're shirts are they're what we demonstrated you see is exactly the same chemical reaction first of all interpreted by the alchemists as a process for making a noble metal from a less noble metal then we've seen it as an exothermic reaction giving off heat energy and finally we've come to the most remarkable demonstration that it actually is making electricity as well now the reason why it's making electricity is because there is a transfer of electrons and that's the most sophisticated and difficult part to understand and the person who first conducted these experiments was a great Italian scientist Alessandro Volta in about 1800 and he was the first person who make electric cells thank you we finish this we can take all this stuff away and we can now start getting ready the thermite's cage please thank you very very much indeed we're now so I've showed you now some examples n of redox reactions don't rush don't take it easy I'm sure I'm sure will carry on even if everyone else leaves if you guys have a wonderful program like I'm very very keen to get through these I just that I love doing these experiments you must excuse occasional mistakes it is a huge hoo-ha setting all this stuff up now what I want you to what I wanted to show you next is an experiment which once again and demonstrates this difference of reactivity by the way can I have the next slide please the next slide please which is thank you very much indeed if we set that up on there in the middle the next slide oh yes that's why they see not just a close-up photograph that's just a close-up photograph of iron having reacted with the sulfuric acid and left to stand for a few days and that's a close-up showing the iron having gone rusty on exposure to air and tiny crystals of green crystals of iron sulfate and then it's beginning to show those little white spots now it's the alchemists would have thought that's fungus growing or some sort of growth it is in fact the phenomenon of efflorescence if we can have the next slide please this shows you the electrochemical said this is just a few a few of the elements you've seen lined up in order of reactivity with the top of the bottom potassium calcium sodium agrees aluminium zinc iron hydron copper silver now this series was first devised by an Italian scientist Volta and he didn't attach specific volts but the effects of the different metals on his body he used to connect up silver and zinc plates and then connect the wires across his forehead across his eyes and things I just get horrendous shots and depending on how big the shock was he then knew how far the metals were apart but from a point of view of today so what I've done is electrical reactivity series the volts are given on the right just to show the volts they generate and you see iron is - point four four and copper is point three four we should theoretically have got point seven over volt but we got point three which is fine but what I wanted to show you next is the the idea of aluminium reacting with iron oxide as many of you notices two spots about art and in this very very simplified table and what that means is any metal will displace and a metal which is lower down from its compound so what we've got in this beaker here is a mixture of aluminium powder and iron oxide and I'm going to show this is a hugely exothermic reaction it releases an enormous amount of heat energy and for that special purpose I have built a cage here this is a thermite cage here iron melts at about 1500 centigrade and and what it does and what it does it will it will that temperature will be reached here in fact this reaches about 2,500 it's an amazingly high temperature so we have to have this specially prepared enough in a far you know container that now this will release some smoke by the way the smoke will almost all be contained in there but I do have to say and Don and Marjolaine will carry it out afterwards you see because they will take the cage off put it on there and then wheel the trolley away and I will show you what's left behind but this you see this beaker is made out of heat-resistant glass it can easily withstand 900 degrees centigrade I'm going to now pour into it I'm going to make up a small quantity of a fuse powder for this purpose I need a small piece of paper ah it's okay I'll just take a piece of paper here a small piece of paper here a tiny amount of a fuse powder made from potassium permanganate there and a tiny little bit of magnesium turnings sorry I've got the wrong stuff out here I've had some magnesium turnings I don't do I have any make the odd where do I have no I don't too bad I'll use magnesium powder instead it's much more violent but that's tough cheddar I just have to have to get on with things I'm sorry about that this it's just setting this up to top amazing as you can imagine it was a thing but we have to get through now we carry on here we carry on here and as soon as this is over we can then out by the way we have some beautiful minerals to show because this is this ant can we bring all those lovely minerals please excuse me I wanted to show you we have three wonderful minerals which are because this type of reaction is used for the extraction of iron in furnaces and they are made from minerals from which the other element is extracted in two of their minerals some are you'll be able to do that these have been linked to us especially for this evening by the Natural History Museum in South Kensington and there they are and allow me just to show you briefly what they are this here is popularly known as fool's gold you'll be welcome to come and touch it this is iron sulfide and it's one of the oars from which iron is extracted releasing hugely self furious fumes and for which we can make sulfuric acid this here is hematite which is red iron oxide which is the same stuff that I had counsel as fe2o3 this characteristically this was formed from the molten state at some stage and this one here is magnetite fe3o4 the magnetic oxide of iron which got these beautiful crystals each of these three are minerals from which iron is extracted commercially on a huge scale the annual production of iron in 2012 was 1.1 billion tons it is the most widely used the most universal thank you very much just take those back in the meantime in the meantime on we go now this I mixed in some potassium some potassium permanganate with a tiny smidgen of magnesium powder that will make one a very very bright flash but it should set our mixture off which which which is a thermite mixture etc now as I said I'm I really am disappointed I didn't have my magnesium turnings right so here we go I'm going to now set this off though with another fuse power this may not work I have to say because I am Not sure that I've got the right fuse bug but it's one just has to proceed on so I've done what I think is a sensible amount of each I'm going to because of the extreme violence of this reacts takes about 30 seconds by the way once I set off you will see a bright flower you'll see a flash you'll see a lots of smoke produced and then we shall then be able to inspect hopefully the product let me just have this this and this year I'll have all my relevant songs and so I'm going to pour on a small quantity of glycerine which will ignite which has a 30-second delayed action response so it's not immediate there we are please take your time don't hurry it's a third about 30 seconds now if you both stand back a little bit if you both stand back a little bit what we're going to see hopefully is a bit of a sort of thing a bright flash followed by and there goes our firm eye that is white-hot 2500 degrees centigrade it is steel this is iron being made now what we're going to do is we're going to examine the products in a second with Marjolaine and Adam will very carefully lift that off thank you very very much indeed and carefully wheel it out that's very very good indeed thank you so much indeed just very jet and I will inspect what's in here you see and if you look here carefully there you can see molten iron pouring out through the bottom you see and our beaker has got a hole which has gone right through it what I'm going to do next what I'm going to do next is to examine I should have a fireproof mat it doesn't matter I'll get one from here I'll just borrow this brick for a second and we'll just put this on here we'll put this on there and we'll just have a quick look at our sample of iron which we've made in there it was molten we'll just pop it into the cold water there and let it boil away there it is boiling and bubbling and very shortly I hope to be able to take out a piece of solid iron what's the other product of course is aluminium oxide the chemical reaction is aluminium plus iron oxide makes iron plus aluminium oxide that should by now have cooled down to a satisfactory temperature we'll be able to pull it out and there we should have a piece of iron at the bottom which will use a magnet to pick up have we thought there's a small bar magnet somewhere on Taccone now fire up please the steam engine thank you very much it's something patching fire something there we are there's our piece of eye and you see so there we are there's our piece of iron which we've made and then though this is Joseph's so it's a successful reaction you see at demonstrating the huge power of chemistry now Marjolaine is we're going to now go on to the mentality and the technology of iron and we what we can do in the meantime dear dom is let will let this cool down for a little bit okay i just what while modulae is getting the steam engine going and dawn will fire up the train set and then we've got also the Meccano model to show you just a few little bits of pieces yes please everyone knows that the Industrial Revolution was a period was a period of the 1970s every seventeen seventeen hundred to eighteen fifty something like that it was a time when a huge amount of progress was made in our understanding of Science and Technology and masses and masses of power was converted usefully and that was all thanks largely to the strength of iron and told you that but their huge understanding of the principles of the reactions of and how steam is produced and how it expands contract a huge amount of chemistry physics metallurgy all going on at once gave birth to the Industrial Revolution there are I've got a whole load I've got four just four books here anyone who wants to look at hugely interesting beautiful pictures illustrations and so forth the train this is a train that just a model railway said this is models which were very fashionable in the 1950s you see and a locomotive there you're more than welcome by the way to come up and have a look at later on here we have a lot of model of a live working steam engine which modulating will set up it takes a few minutes so please don't expect results but more today could we just show us the Meccano while we're waiting for that could you please show us this this is a Meccano model of the type that was very fashionable Meccano sets were fashionable in the nineteen well from the 1920s right through till today but their heyday was sort of 1930s to 1950s and modulate has wound up the motor and that this is a working model it took us several hours to make by the way it's not easy to make these models and another run there just to show you there it is were sort of working the model and would be Meccano sets could do they could they were all made out of steel which they represented items of technology which people use on an everyday basis the people who are responsible for steam engines by the way there's a huge history may I recommend that you visit the Science Museum if you haven't done so already fantastic exhibition on the ground floor of steam the history of steam power it was that goes back to about 1700 about 1700 with Thomas Newcomen and the condensing steam pump the reason by the way why pumps were made in the first place why steam power was developed in the first place was to lift water out of mines we have always relied hugely on mines for minerals minerals for which we can make metals and also of stones of cements and other such like substances also jewels and so forth so mining has always been part a part of the great human tradition and the deeper you go the more likely that mines were to be flooded so there was always a need for pumping out water and that was the main reason are we ready almost to go no no no hurry at all I've got that I will keep them that should be ready in a couple of minutes and marginally his well-tried entities so steam engines initially what worked on if they were reciprocating the piston it used to just go up on one side up on the other there was no pressure involved they were called condensing atmospheric engines after about about 1800 James Watt brilliant Scottish engineer came and developed more efficient technology for condensing the steam or for given to building up pressure and he invented he was the first person that she started making the instead of the just going up and down to pump up he had met you made steam engines where a wheel was turning with an example of which we've got here they were static steam engine now these steam engines covered the whole of Europe there were thousands of them everywhere and you can see if as I said several of them are on display even full-size ones at the Science Museum but this is a model which demonstrates the principle the principle is as follows the water is boiled in a boiler and this is where iron comes in steel iron has always been the strongest easily available metal and boilers were made from steel and all the components the engineering components the crankshaft the con rods everything was made out of steel and that is why it is so ubiquitously in use and the largest the iron mine of iron today I believe is in Brazil huge area and they they go several it's an Edison opencast mine several hundreds of square miles and iron continues to now please notice our experiment is 100% successful there water has gone right up into the flask and it will fill as you probably know about one fifth of the air is oxygen so this is a one liter flask we'll eventually have about 200 cc's of a color liquid in by the time that particular portion of air has been used up now are we getting there slowly no trouble at all right in that case carry on my dear we'll move on to the next topic which is magnetism and I just wanted to tell you that around the end of the 1700s around the end of the 1700s there were two huge advances in science in one in chemistry and the other in physics concerning invisible things invisible phenomena in chemistry it was the chemistry of gases they were invisible and people for the first time were able to identify gases recognize them and test them that was one invisible the other invisible phenomenon so we have the balloon experiment just to show please have you got that there we other bad balloons down there the other invisible phenomenon which have been known for thousands of years was this one here and that is what you all know and we're going to now show you what happens invisible forces the balloon is now sticking to the door that the children is what we call static electricity so electricity static electricity was one phenomenon and the other remarkable phenomenon was the one that we have here and that is a magnetic and magnetic phenomena and it had been known so please demonstrate without carry on talking please demonstrate that my dear Tom the the effect of the electric current is once you've got it I'll tell everyone what's going on but the fact is that magnetism was something which was of great interest people knew that they knew in nature that a lodestone which is actually the black iron oxide that I showed you those crystals fe3o4 is magnetic and people have picked up these stones and it wasn't they were used by Chinese explorers thousands of years ago they were used throughout the world we know we have evidence because they always pointed in the same direction we now know that's called magnetic north and that lodestone but that was a mystery people didn't understand it william gilbert published a book in 1600 of his theory of magnets and we're going to try out to see there we are the steam engine is really to go so I will interrupt and and modulator will now turn on the steam engine hopefully it'll fire up we may take a little while now there's a dead notice could we have the lights dimmed so you can all see what our steam engine is achieving it's got a little light there this shows the inter convertibility of energy this was one of the greatest triumphs of the human race was to harness the energy from burning to produce mechanical power that's what happened with the steam engines thank you very very much indeed modulating that's absolutely wonderful notice the splendid steam coming out etc so this is a model steam engine the real thing the boiler needless to say made of iron and steel because of its sharpness thank you very much Marjorie now Tom will quickly demo I have here a beautiful compass here which has a magnetic needle which has a magnetic needle and it is very very sensitive to magnets which are brought around it and Don will try and demonstrate for now one of the most important breakthroughs in the link between electricity and magnetism it's an Express you could see it turning you can see the needle is turning this is an experiment which was done by us there in 1819 and it linked the idea of an electric current to magnetism now this was the greatest triumph of the great michael faraday supreme experiment and Michael Faraday who parallel with your next experiment while I just say a few things a demonstration of a simple electromagnet because Michael Faraday who weren't in this precise building it's thanks to him that we have generations event we have electricity being generated the alternator the electric motor that was all Michael Faraday's work and there what Don's demonstrating is a simple electromagnet just a coil of wire around that if you disconnect it they they'll fall off that's the point to show if you disconnect the magnet then they fall up so that is a simple electromagnet made with a one-and-a-half volt battery now dear children just to show how modern technology that's a simple elementary electromagnet modern technology has moved forward we have here a magnet we have here another electromagnetic into a slightly straighter position here and this one here what I wanted to say is an electromagnet which is using modern technology which has which is uses one battery there it's exactly the same battery but this is capable of lifting 50 kilograms now we've got just as please you'll demonstrate it now we've got just a 20 kilogram piece of rail and if anyone wants to come and try it afterwards you're more than welcome but believe me this is very very heavy indeed the point of the demonstration is to show you how very very efficient today's electromagnets are from the day when Michael Faraday was doing those experiments there too today where we can get and they have huge application in industry electromagnets this is the reason why that is so efficient is because of the number the design of the magnet and the number of coils to give them maximum magnetic flux they're now on the subject we're now is it on to mid time we've almost finished we're getting closer are we getting ready for our welding if you could just quickly bring in the welding gear a very short experiment on welding I hope you don't mind because this is very interesting I just wanted to tell you a little bit about steels that's still the science of may I just give you this this book here published in 1888 is entitled electricity in the service of man it says written by a German author huge amount fantastic pictures just look at the pictures it's amazing how much was already happening then this this book great engineers I'll quotes from that later on and here metallurgy by Sir Robert Hadfield one of the greatest metallurgist a profound personal supremely interesting book masses of India as I said the pictures in all of these book are quite fantastic now what I'm going to do is to demonstrate for you very very briefly a little bit on welding then we'll have a bit on mentality a bit on blood and then we're finished I hope you don't mind if we're running over by very very considerable margin unfortunately I haven't done this I haven't done this demonstration before like this with all these things which I think coming to the Royal Institution one must show the best of what humanity can do in terms of in terms of giving you an experience to remember something positive now so here we are I'm now going to I require a brick where's my bricks ah then watch out hot no not hot okay thank you very much indeed yes it is hot but it doesn't matter now what we have here now I'm going to show you very quickly because you see all of these things I will show you all of these machines steam engines bridges of the whole engineering world of iron steel and technology you have to join the iron together with something so you have to join it together so the most ancient technology was to use rivets which is you make a hole and then you sort of knock together to bits at the end of a steel rod that you put through and it holds its together and rivets are still very used they used on aeroplanes they used in the naval engineering and they use throughout the world nuts and bolts use but by the pointed with both rivets and nuts and bolts they are both intensely labor consuming so they take a long time to screw the nut in the ball or to whack the rivet together so a technology was developed at the end of the at the the beginning of the 20th century which is all by the way who can sprinkle some iron magnetic power the wire I set this up you see just to show these were experienced once when invisible forces but we can have a demonstration for you Marge I will just show the beautiful pattern which is some of you are familiar with but I just find it so beautiful sprinkle some iron filings on a magnet you see and it shows you feel the magnetic flux now what I'm going to do I'm just going to show you the power of the technology of welding you see welding became possible for two reasons first of all the chemistry had been understood so people were able to make gases and collect them which had a fantastic need so look at a beautiful plan those are the fields of force invisible fields which we can't see normally but the iron filings show them there but what I'm going to show you now is I'm going to show very briefly the technology for joining metals together which is used today there are various types of welding an oxy-acetylene it was possible because to start off with as I said it was possible to make the gases oxygen and acetylene and store in large industrial courses but just as importantly they were able to make cylinders which was strong enough these cylinders are made of steel you see so having divided that they then sought to find out gases which would be which would have a sufficiently high as a sufficiently high temperature when they were mixed to be able to melt iron now just for your information your domestic cookers the flame there burns at about six or seven hundred degrees centigrade you see so that's by metallurgy standards that really is a very low temperature oh I won't bother with a match I'll just use my candle which is burning sorry so please think so this is good to be pure acetylene Catching Fire it become oops-a-daisy is that possible it should have there we are so there's pure aesthetic now this is acetylene which is a gas which is burnt with a hanging around it's some things not quite right shouldn't be going down let's just let's turn off okay I think let's just just check out cylinders yeah that should be okay right so we've got now this is pure acetone ec2 h2 the chemical formula it burns with a very luminous flame giving off quite a lot of salt as you can see going up now if we add oxygen to it as I very short you will please excuse me then the flame will gradually increase in luminosity but will then become a very very beautiful intense blue color and this temperature the tip of this flame is about 2,500 centigrade so that the moment that's luminous but it should gradually turn blue as we increase the proportion of oxygen so we're now getting a typical flame which all gas cookers have a Bunsen burners have with their flame holes open and there it is there now this flame this flame it has it can reach a temperature as I said of 2500 say oh there it dear me you see because I'm trying to many things let me put my gloves on first we'll put my gloves on first okay I accidentally turn the whole thing off that wasn't very bright was it never mind we're we're back in business again let's put on our essentially just make sure they are right that would help if I that was screwed in properly and done that by the properly right as you can see this was all set up in a hurry but try again now we are right so there we are we're burning we're back in action again turn the flame down to a sensible height there let's get our oxygen and now I'll just show you how very very hot this can get indeed I'm better first of all heat a test you which is made of heat-resistant glass and that melts at nine hundred percent agree I just tried should them demonstrate for you the phenomenon of plastic flow so there is our flame there is our flame and if we play that flame on the test you'd there you'll notice a beautiful orange color now that's orange color is due to the sodium content of the test tube the test tube is made from basically a glass in which contains silica silicon dioxide sand and and I'm just going to see won't get plastic flow where it will actually fall but not reach the ground it's a very tricky one to do we'll see we could do it we're melting it but it should please watch ah there we are just about there it is that we see a piece of the you see this here what I've demonstrated is good a drastic flow in glass you see so this is you see glass which we just about managed to catch now what I'm going to do I'm going to actually now attempt to a welding experiment or we can take this away please Dom please excuse me I'm going to attempt to rather than do something boring I'm going to do something a little more interesting which you may not be aware of it's a shot start off by sprinkling some two pence coins which of course are made of copper however if we take a magnet do we have the permanent magnet here there my dear and marginally down there my dear could you please get me the magnet so your children two pence coins are made of copper you see either one of these was of yeah thank you very much now if you see so copper is not magnetic copper is not attracted to a magnet you see that is that's not not attracted so what's the point of demonstrating this you see but hang around that one is magnetic so I'm not quite sure whether I'm demonstrating this correctly so that's a copper coin but it's actually not copper this one is that one is that that's cop that's magnetic that one is that copper isn't magnetic that is hang around this is very odd that one's magnetic and that one's magnetic that one isn't that one isn't so what I'm demonstrating dear children is the most interesting thing is that actually two pence coins can be made either of iron ore of copper and this is a cheat you see they're not actually made of copper they're made of iron but coated with a very very thin layer of copper you see so because they're made of iron and the reason why this happened was in 1989 it became more expensive the amount of copper used in a the amount of copper used in making a 2p was more than the 2p pence was worth so people would melt down two pence coins and get rich that way not a very economical way but never there now could we have the beaker of water with sand in it please don't you remember the one we'll put a thermite mixture in thank you very very much indeed what I'm going to do now I'm going to therefore I'm going to show you that these are made of steel by and by creating a very very unusual coin if there are any coin collector see I'm going to make an 8 pence piece you see so I'm going to weld my 4 coins together thank you very much Dom there that was yeah that's fine that's fine it actually no you're right on the table on the table Dom Dom it's really quite extraordinary - they're both amazing that now in order to weld them together I need a welding rod which I've got here you see so this is by the way very very difficult welding under any conditions let alone at the Royal Institution but I think again in the interest of Education we must show you what is for the possibilities we don't have my goals out here yeah by the way I have to say the goggles are mainly I mainly to an able you to see better this is not an intrinsically dangerous process like arc welding or MIG welding where the temperatures reach would damage your eyes this is merely so I can see better now now I will probably have to stop talking what I'm doing but I'm going to carry on talking as I can't stop talking now what I'm doing right this is a very tricky operation I'm heating up the 2 pence coin which is made of steel as I demonstrated and I have to get to hot enough in order that I can melt some this this rod which I'm holding right I've made a four pence piece we're now onto the next one you have to heat up you have to develop sufficient thermal capacity to actually melt to melt the steel it has to actually flow and the trick is if you melt it too much then the whole lot just catch fire and burns when you're left with nothing so there's a quite - fine quite a fine margin there's not much scope for error in this but we've got a 6p coil at the moment so and the thing is because iron and steel are so very very very strong but then we then the joint is very very firm and welding has huge applications in industry think we're there actually now I'm going to put this down here turn these off quickly one two there now what we do now is we pick up our 8 pence coin and we lob it into cold water to cool it down and now we have a look to see our product whoof that's quite hot there we are there we have lead and gentlemen and eight pence coin this will be very useful for anyone could you imagine if you've seen this shot if you've seen this shop something you want to buy for eight pence instead of fumbling around say one p2p just say eight pence now this is wonderful so you see always we could always meant now thank you so much we're now ready thank you let's just move to if we could take this out indeed thank you very very much indeed what was next on the list of we're almost there now if it's a metallic oh I know metallurgy and then the final one yes I did is that right that's right is it metallic right dear children I very nearly finished just a few little bits and pieces you see you see the different types of carbon different types of steel depend on two things how they have been heat treated in the foundry and secondly how how much carbon they've got in a typical mild steel contains about 0.1 percent carbon not much at all and I've got the exact mild steel is this thing here it's what most things are made of here I've got a piece of cast iron cast iron is used hugely it's strong but it's very brittle whack it one with a hammer and it splits apart here we have tall steel high carbon steel used for cutting tools etc and here we have spring steel spring steel used to store energy you wind it up and I've got my beautiful pocket watch here which tells me we're way over the little Michael in this almost well the five to eight to tailor that's that's wound up with its previously and another application you see people have made use we're selling that we can make use of Springs in musical instruments the piano for its has steel wires which I break but the mouth organ has steel reach so I'll just play with the polish folk tune on this one let's we'll get it right way around but [Music] thank you very much for that spring steel in activity now we've got almost all I'm going to show you quickly another heavy-duty this truth of the starter motor that starter motor quickly let's start to motor than the foam I thought ok have you still got the energy maybe there we've got plenty of energy I'm so sorry you have to leave early steel they do what Michael Faraday invented the electric motor these by the way they have call we have breeze the couple of slides Michael Faraday's original electromagnet is here that's one of his original extra man it's on display the Royal Institution here they have a fantastic display and I cannot open it cuz I one could do a whole talk on Michael Faraday his life and his work but it is he invented he was a profoundly humble man he wanted no glory he just wanted to serve mankind who was really a to and please the next one the first ever electric motor doesn't look like an electric motor but that thing's spun around there was mercury in there and each other that little needle it's spun around the central a central thing in the essential pool of mercury when the current was when the occurrence was past I don't know how it works where the fact as it does now I bought here the honest truth is this is an electric motor used for starting a motor cars every single time you turn the starter key what happens well this is what happens and that's a starter motor you see but these when the starter motor goes around so what the thickens and does it actually do thank you very much I'll now thank you very much as brilliantly demonstrated I'll just show that and now would connect up the finisher so when you turn this you see say well what happened off does that start a car well I'll show you we're now going to quickly construct parts of a car I think it's very important do we have some beautiful this is parts of a car this is part of a differential gear box please pick up one tool in the other and I'll get this is beautiful by the way all lorries have this you know and all of this and the Triumph Herald motorcars he seen some trials brilliant engineering and there the reason is it's simple easy to take apart put together nothing both technologies and the point is all of these things are beautifully made and they're mass-produced mass production it's what which is the hallmark of today's industrial revolution and what we're going to do is just to show you how it connects up now this ship is a flight wheel you see so when the starter motor turns and this tiny gear here engages onto the flywheel here and we'll just quickly build part of a car to show you and there it is I will hold this I will hold this and then now this is by the way this year you will all recognize of course is a crankshaft it's a tranche off with one piston in it and because let's starts will just locate it and I think it's very important in a lecture on iron and steel to build part of the motorcar after we we all use motorcars we all use motorcars on an everyday basis we take them for granted and marginally will now very quickly insert five brothers allocating there's a locating screw there we go we're in modulating we'll quickly locate four set screws and then tighten them up and we'll be almost ready to drive off but we'll be ready to do the the almost the final experiments which I think we're is that right the last ones to go thank goodness we need you there now we're very nearly there I please excuse me there we go let's just tighten this up now here we go using a socket there 5/8 inch socket with a t-bar on it and this is the sort of thing we do it automobiles society with dismantle we build things and cars you know and I cannot recommend that the enjoyments of fixing something yourself you know I think that everyone those that the great satisfaction of doing something yourself you fixed it you made it work and you have you feel it's a great great sense and there a little bit of practice and anyone can do it and there we are Marg Lane has just connected the PM the flywheel to thee there we are and all of this is beauty FLE precision-engineered than the dinner what's amazing is this tiny motor this tiny motor has enough torque to turn that whole thing over and get the car going so there's that one there and now we're on to the final the final demonstration of all and that is and that is all just one thing and this is not a demonstration you don't have to worry but it's just to tell you about of course I am in biology and of course do you all know that we have about 6 grams of iron in our blood we all have I it doesn't flow around in the form of iron filings it flows around in a form of hemoglobin the bread coloring matter in our blood cells and that iron plays a most important role in our physiology in a way in way we live and breathe now what we've got here is two hydrogen oxygen balloons and this and the purpose of this you see is to show the enormous resistance to heat of steel this is a steel rail and in it we're going to put a flash powder which consists of magnesium and potassium magnesium potassium chlorate now that flash powder generates a temperature about 2500 degrees centigrade which if there was enough of it it would most definitely melt our steel rail but now could we just quickly that we mustn't waste now balloon up they see that balloon there is filled with hydrogen and if you don't mind I cannot bear the prospect of I'm having a balloon filled with hydrogen going up now I do repeat that these balloons these balloons filled with hydrogen could you just hold it down there thank you very much so there it seriousiy we're going to ante if I tell you what we could just secure it secure it someone I'll quickly light it with a burning splint just hold it there it would just burn it off it's not very spectacular I have to warn you but it's nevertheless it's important that we don't waste good chemicals so I'm just going to set fire on that Oh it mustn't set fire to these two that would be a terrible disaster these by the way are filled with a mixture of hydrogen and oxygen you see and they will make a very very loud bang if the experiment works so this is just a balloon filled with pure hydrogen which we made earlier on it burns with an orange flame it's not particularly loud but it's rather fun so there it is you see that was our that was out now that and now for our very final experiment for our very fine no no no please the final experiments now may I please now may I please I'm going to make up a small quantity of magnesium magnesium flash powder now and this I have to warn you we've got a burn with an exceedingly bright flash so and it sparks will fly sometimes they go a couple bit almost certainly we may be sort of poor get ready to squirt water okay on anything is let's catch fire Adama you read do we have another squeeze squeeze bottle doesn't matter just pour a beaker of water on it but it should be okay now I'm just sorry now what we do is we mix this magnesium powder you know I'm so nervous my eyes are frosted up I just have to take those off if they steam up I had six pairs of safety spectacles but in all the hurry I just don't know where I put them didn't I put one that does it oh there's one that doesn't steam up thank you very much these these are very you must understand this is nothing these have to be worn if they're sparks which are likely to go behind these are not these are just good for for making a sort of you know liquids and standard laboratory where the other ones are industrial heavy-duty safeties but now here's then our magnesium pad and I've got to make sure that it's smooth because if it's not smoothly powdered then it will then it's there are liable to sparks are liable to go somewhere South another sheet of paper if you'll excuse me thank you very much Tom thank you very much just a tiny bit here and I have to be very careful the quantities a it's all slightly by rights the it's an art rather than a science what I'm doing now is just mixing them together in hoping and I'm just double checking but now we have to mix them very very carefully indeed very carefully indeed and at the end what I'm going to show you is that even though hopefully there will be two loud bangs and hopefully there will be a blinding flash this will still be intact which is out the main purpose of the experiment now please excuse me why now just for hang around I'm just going to pour them from one sheet to the other we have to make the fuse powder as homogeneous as possible there it so I'm now going to very carefully now I do a repeat if there's anyone who's afraid then I would definitely leave this will make a profoundly loud bang and also there will be a quite a little cloud of smoke which will go up but I've been reassured by the organizers that smoke alarms are fitted and and and that the air will become very fit to breathe in a short space of time offices so now I need some potassium permanganate we use a as I said potassium permanganate goes in here yeah well ah there we are just a little bit there and to that we're going to add some glycerin and then I'm going to I've got to actually show that it's survived but perhaps it will be good to have this this is a very very bright flash indeed and if we dim the lights I think that will be very satisfactory so I have one now I do repeat the warning these does make a very loud bang this does and it does send up a large and there'll be two loud bangs and a large cloud of smoke and this will be the definitely the last experiment so after that I will hold up hopefully and I wish you all a very good evening I hope you've enjoyed learning something now here we go so there's our glycerine now as I said it takes up to 30 seconds before the mixture actually takes off so we'll stand back and watch then my suggestion is you don't look at it too directly that you sort of look at it at a slight angle etc there it goes so well we're watch out careful there it is so have lights on please thank you very much indeed so there is our thing having survived thank you thank you very much indeed marveling thank you Tom thank you very much indeed we'll turn out to the front to take about come to the front with me thank you very much to the Dom come here so there are my two assistants my two assistants thank you very very much indeed our very very best wishes very very very - thank you so much indeed thank you very much [Applause]

Channel: The Royal Institution

Views: 1,666,649

Rating: 4.6913357 out of 5

Keywords: chemistry, science, explosions, iron, steel, buring, andrew syzdlo, ri, royal institution, science communication, education, teacher, fireworks, experiments

Id: Na7Bp4frYGw

Length: 116min 43sec (7003 seconds)

Published: Wed Mar 11 2015