Chemical Weapons (Sarin Gas) - Periodic Table of Videos

there's been quite a lot of recent discussion about chemical weapons so we thought it might be useful for you to know bit about their chemistry so that you can understand the discussions rather better so I know a little bit about some of these things in particular nerve gases just because some of the research I do looks at the nervous system how we can interact with it actually to control pain rather than kill anyone the use of chemical weapons really began in the First World War first of all they use chlorine which is a sort of yellowish gas so you could see it coming across the battlefields you had trench warfare these would go along no-man's land down into the trenches and obviously maim and kill the the enemy or if you got the wind direction wrong your own troops mustard gas which is chemical weapon which was used again in the iraq-iran war in the 1980s is although it's called the gas it is actually liquid which made it particularly unpleasant because it would persist on the battlefield for months mustard gas that was shot in the autumn could still be there in the spring and affect people and it caused blindness for those people who were not actually killed by it but the rather macabre twist to the chemistry of mustard gas is that it has since been used or derivatives of it have been used in medicine and more people have been saved by derivatives of mustards then were killed in the various uses on the battlefield run up and in particular in the early stages of the Second World War I guess both sides allies and and the Nazis they were both developing more sophisticated chemical warfare agents presumably in case the other side used it luckily although the lots of developments were made luckily there was no chemical warfare whatsoever in the Second World War and none of these items got used but nonetheless the technology had been developed and so these days there you know there is some knowledge out there about these more advanced systems of which sarin is one of them unfortunately terrorists can get hold of it I've got a molecule of sorry here not real sad not real sorry nowhere that would be illegal to make that I've made it out of straws and these colored balls they're quite a small molecule not many atoms and that's why it's volatile it's a gas or a very low boiling liquid here we have a phosphorous this purple one these two red ones are oxygen the black ones are carbon and the thing which makes it the reactive and volatile some extent is this one here this is a fluorine and what this does is it blocks something in all animals are humans called acetylcholine esterase that's the what it works on there was great worry in the UK that chemical weapons which by the time of the Second World War were much more sophisticated might be used so all British citizens even babies were given respirators or gas masks and I've got my father's gas mouse I think they were presented in the cardboard box but my father had this rather posh leather case made for it and if you look inside it has his name he's written a Polyakov Esquire and he's got his dad read his work address and even his telephone number inside is the gas mask itself I haven't taken it out for many years and I think it might be perished but let's see if we can get it out so what is acetal choline esterase well before I tell you what the esterase bit means I'll tell you a bit about austell choline so this is a molecule here of acetylcholine and this is a neurotransmitter so whenever we breathe or move our arms or do a whole range of things heartbeats and whatnot we use our nervous system our brain sends a signal now throughout most of it it's like an electrical cable but when it gets to a junction those signals are transferred by neurotransmitter and Estelle coding is one type of neurotransmitter so this drifts across the synaptic gap the junction and it triggers the next response and that response might be the arm moves or lungs breathe I think I may need to stand up for this so here are the straps but let's see what's left inside when you want that response to die off what happens is this drifts away from its receptor and a molecule like a pac-man comes along and choose this up and that molecule is called acetylcholine esterase so that's the totally natural very good thing very good thing because otherwise if you move your arm it would always be there you wouldn't be able to stop it and going to come back and breathing you'd be always breathing out not breathing in something coming so here we are this is now completely come off and there is an eye piece and the thing that you breathe through so you need this to go on and this happens you know in milliseconds is incredibly quick incredibly quick and all that happens is that this acetal choline esterase comes along and it takes that end off this is now vinegar over here and the other bit is choline and that gets recycled to make more estelle choline in the receptor end well you can't see very much it's a bit dirty I can just about see the camera I couldn't drive and this and what it would have been like walking in the complete darkness of blackouts I have no idea so that process is going on and on and on constantly in our bodies and what sahrin does is it comes along and the molecule which which takes this ends group off here let's let's call it this I think it's this Oh H which is going to happen in the pac-man's and that's the the pac-man molecule comes along it swaps that for that and then water comes in and takes this off to make acetic acid well sahrin comes along and it's got a much more active group the fluorine is really reactive that goes and this attaches on but now water can't take this off again so it's just soaked up one of these pac-man molecules estelle choline esterase molecules well now you see it's not available to break down the acetylcholine in your body so you've always gotten on switch on your muscles and the thing which is deadly is your breathing because obviously your lungs and muscles they move in and out and if they don't go one way and don't go back the other way then you know you're very quickly die of suffocation which is why you see in all these news reports people with no really bad breathing problems and it's because they they can't get those muscles to work correctly because the acetylcholine esterase has been mopped up by the sarin and the water can't hide rise inside here will be activated carbon like a charcoal which has a very large surface area and will absorb the molecules of the poison gas and I believe they are not certain that they found that coconut charcoal was by far the best why from coconut I don't know it just probably gave a higher surface area so there is an antidote and of course whenever chemists have designed in the past poisonous things obviously they don't to kill themselves they're clever guys they invent some sort of antidote and the antidote is this molecule is called prowl daxing and this is like super water so here's an oxygen here and it's connected to this nitrogen and that makes this oxygen about hundreds of three hundred times more reactive than normal water and that can come along and displace the sarin from the acetylcholine esterase that can go back its business again now the other thing which is perhaps more interesting is this which I bought as a schoolboy in the early 1960s as far as I remember I paid five shillings for it 25 UK pence and 60 you at that time sixty US cents so not very much inside if you look this is a kit a military kit for detecting poisonous gases and here the instructions how to use it here there's a whole Lab of little different vessels and underneath is essentially what is a bicycle pump except instead of pumping things up it sucks air through a hole at the top you put the chemical tester here and then you pump like this and it sucks air through so you've got imagine me now wearing a gas mask and gloves because they may be chemical it was that you put the thing in here and then out of here you took a small paper disc so imagine wearing gloves and the battle raging around me and you put a chemical this piece of filter paper in here and then you start mixing up solutions here and start pumping away and see if you get a color does this stuff scare you yeah totally absolutely yeah yeah I mean it's horrendous that the lethal dose for this it's around 1 milligram far smaller than the smallest soar sweetener pill that you might put in your coffee for example we think of cyanide sodium cyanide is being quite dangerous be neat so 1/2 teaspoon full of that so you can see that these are these are you know around thousand times more deadly than even cyanide and we all know that that was horrendous I think one of the problems of chemical weapons is that they are not targeted at particular individuals in the way that you would if you shoot a gun at them you can't control them I'm if you aiming a bomb or missile at building you're aiming at that building but if you release a gas it's going to go over the wind blows it and there's no control of hosing the way and who isn't also that the members of society who are most vulnerable old people young children are those that are likely to suffer most from chemical weapons because if you know their chemical weapons about and you're properly equipped such as soldiers with all their battlefield kit then they're relatively little danger you cannot easily protect yourself from exploding bombs if they're big ones but you can from chemical weapons so part of the revulsion I think that everyone feels about chemical weapons is that they're not targeted individuals and innocent bystanders can so easily be injured or killed so look at the blue one the nitrogen this is a cation that tetraman trami fel ammonium species there is a huge problem now that there are aging stockpiles and various places of chemical weapons that need to be destroyed

Channel: Periodic Videos

Views: 1,087,560

Rating: 4.9513702 out of 5

Keywords: chemistry, periodicvideos, professor, nottingham, chemicals, elements, Chemical Weapon, Sarin (Chemical Compound), mustard gas, Sulfur Mustard (Chemical Compound)

Id: jozozH09XSs

Length: 12min 52sec (772 seconds)

Published: Mon Sep 02 2013

Reddit Comments

[u/chemellow]

This was a very good summary of the very chilling reality of sarin. Love this guy's videos!

[u/nullvoidnullvoid]

Found this video: Whispering Death: History of Chemical Warfare Agents

It's more detailed, and also talks about other CW.

Scary shit.

[u/stop-chemistry-time]

There was a paper in the Chem Commun feed this morning from Philip Gale's group. It describes a supramolecular sensing system for an organophosphorus agent. Quite neat chemistry.

P Gale et al., Chem. Commun., 2013, Advance Article; doi:10.1039/C3CC44841J

[u/Edgers]

Very well explained - fascinating.