Making Sugar of Lead

let is a toxic element and it's generally known to be avoided for survival purposes you would expect to lead compounds to taste bitter and terrible but weirdly enough a lot of them are pleasantly sweet the most famous one is probably lead acetate which has kind of had an interesting history the ancient Romans used to make a syrupy sweetener called sapa by boiling down grape juice in lead pots this resulted in the formation of lead acetate crystals which were sometimes visible in the sapa because it looked and tasted like sugar it eventually became known as sugar of lead however even though lead acetate is sweet it probably didn't contribute too much to the overall sweetness in modern days people have replicated the Roman recipe and they get a lead content of only about 850 milligrams per liter considering there's about 200 grams of sugar per liter this isn't very much it seemed that the major reason why lead vessels were used over other metals was that it avoided the formation of bad tasting metal acetates like copper acetate until the 19th century lead oxide or lead metal was frequently added to bottles of Port or wine as they aged if they were exposed to air some of the ethanol could be slowly oxidized to form acetic acid the acetic acid would then react with lead to form lead acetate a common myth is that people did this to sweeten the wine but it's likely not the case just like with the Romans in the Sapa although lead acetate is just as sweet as sugar there's not enough present to give any real sweetness however it can sometimes be enough to kill microbes and prevent the wine from spoiling unfortunately the concentration was sometimes high enough to poison the drinker so the practice was eventually stopped by the 19th century people were well aware that lead was toxic but it was still commonly used in medicine lead acetate was found in many pharmacies and it was mostly used to treat intestinal problems like diarrhea it apparently works pretty well in small doses but a lot of people accidentally poison themselves nowadays lead acetate has only a couple limited uses like in some men's hair coloring products or to detect poisonous hydrogen sulfide gas it can also be used to make the high explosive lead azide but that's pretty dangerous to do in the future I plan to do the much safer demonstration called the tree of Saturn okay so to make the lead acetate we can do it in two main ways either from lead oxide or from lead metal I originally plan to only make it using one method but in the end I ended up doing both ways to start things off I'm going to show you guys the easier method which is from the lead oxide to do this all I used with some glacial acetic acid and lead oxide that I purchased online instead of buying it it is possible to make it yourself by tearing apart some car batteries removing the lead dioxide and roasting it to convert it to the lead oxide anyway to start things off I need to make roughly a 50% acetic acid solution to do this I mix about 55 grams of water with 55 grams of acetic acid I continue to let it stir for a little bit and now it's time to add the lead oxide at first I only had a small amount so you guys can see what the reaction looks like the reaction between lead oxide and acetic acid produces lead acetate and water because I'm doing this in the presence of excess water the lead acetate that forms is the hydrated form lead acetate trihydrate there's no gas producing this reaction so I think all the bubbling that we see is just from air that was trapped in the lead oxide also because I'm not stirring anything all of the lead acetate that forms dissolves into the lower portion this greatly increases the density and two layers have formed because of this okay so at this point I think I'm done playing around with things so I dumped in the rest I then turn on strong stirring and I wait for everything to dissolve this reaction generates a decent amount of heat and we can start to see some water vapor coming off it dissolved pretty quickly and it only took about three minutes to completely disappear however if you look closely you'll see there are a bunch of impurities floating around and I need to filter these off this is very easily done by just passing it through a coffee filter once everything had been filtered I washed the beaker and the filter paper with a little bit of distilled water the funnel is taken away and I wait for things to crystallize I left it out for about a day but when I came back there was still nothing this can happen sometimes if there's no place for the crystals to start forming so to get things started I drop in some lead acetate that I already have I also could have used just a little bit of sand or scrape to the bottom with a glass stir rod right after adding it we can see little crystals starting to form and then it just takes off the reason this happens is because the solution here has been supersaturated with lead acetate as the original solution cooled and as some of the water evaporated the solubility of the lead acetate decreased a lot however because there was nowhere for the crystals to form it was all forced to stain solution this leads us to having a concentration of lead acetate which is much higher than the normal solubility so once I provide something for the crystals to form on all of the extra stuff quickly falls out of solution I left it for about an hour and then I came back and broke it apart using a stir rod all of the crystals that we have are quite small because they didn't really have time to grow to get larger ones the crystallization has to be much slower and it has to occur over days or weeks and not just minutes at this point if you don't care about the size of the crystals you can just keep evaporating off the liquid until it's completely dry the purity in either case is probably about the same but I really wanted some nice crystals so I went ahead and filtered the liquid portion through another coffee filter unlike before the solution here isn't hot so we don't have the problem of it cooling down and becoming supersaturated the only thing that will decrease the solubility is the evaporation of water and this should happen pretty slowly and just for good measure I drop in some lead acetate to really make sure it doesn't get supersaturated again the filter has a bunch of lead acetate with it so I leave it out to dry and then I combine it with the other stuff now it's just a waiting game for all of this to dry out and for the lead acetate crystals to form in the other Bowl over the course of about a week we start to see some nice crystal formation I then left it for another week or so until all of the water was gone I spent a few minutes admiring the crystals but then it was time to remove them using a spatula I scraped them off the bottom but I tried to be as gentle as possible it's inevitable that some of the crystals will break but I want to keep this to a minimum eventually all of the crystals were scraped off they were still a little bit wet though so I dumped them out onto a piece of paper and let them dry a little bit further at this point the lead acetate in the other bowl had completely dried up as well so in the end these are all of the crystals that I got unfortunately the stuff on the left was a little bit yellow the total mass of everything here is slightly above the theoretical because there's still a little bit wet anyway now I'm going to take a look at the crystals starting with the larger ones I picked out a couple that I thought were the nicest as well as a cool cluster that formed the crystals of lead acetate trihydrate all have the same basic shape they form rectangular prisms with a parallelogram as a base unfortunately though the crystals here weren't large enough to really showcase the structure at first glance the smaller crystals looked boring but when I zoomed in they were actually kind of interesting it might look like things are in fast-forward here or that the video is jumping but this is actually how it was because the crystals are so small static and small movements have big effects if I scrape the paper too hard the needle would jump a little and cause the crystals to bounce it took some effort but I was eventually able to isolate one anyway the crystals here weren't the greatest and I thought I could do better instead of just trying the same process again I decided to make it from lead metal to do this I'm going to need three things lead metal glacial acetic acid and concentrated hydrogen peroxide it is technically possible to use 3% peroxide and vinegar for the acetic acid but I really don't recommend it because it's going to be super slow also the lead acetate solution would be really dilute and it would take a long time for all of the water to evaporate to start things off I add 15 milliliters of water followed by 81 milliliters of acetic acid on top of this I dumped in 75 grams of lead pellets with everything loaded into the flask I set up a cold water condenser above the condenser I attached an addition funnel which is preloaded with the 30% hydrogen peroxide then I turn on the stirring and I start to add it slowly the addition of the peroxide is exothermic so the reaction mixture is going to start heating up the goal is to keep adding it until the solution reaches its boiling point and then to adjust the rate to keep it boiling only slightly okay so in terms of what's going on here when the hydrogen peroxide is added it reacts with the lead metal to form lead oxide the lead oxide then very quickly reacts with the acetic acid in the same way that we saw earlier in the video the reason why we need the peroxide is because the acetic acid is not strong enough to directly oxidize the metal historically when lead was added to wine the oxidizing agent was just oxygen from the air so in theory if I didn't have any peroxide I probably could have just pumped air through the acetic acid but the reaction would have taken a really long time after a while the addition of the peroxide is not enough to keep it boiling so I have to turn on the hot plate eventually all of the large pieces at the bottom have disappeared but there's a lot of small particulate still floating around I tried to get rid of it by adding more peroxide but I might have gone a little bit too far I kept adding more and more hoping it would disappear but it didn't seem like it helped too much I turn off the stirring of the heating and the particulate quickly sinks to the bottom I think this is mostly just finely divided lead powder but I'm not exactly sure why it's not reacting anyway regardless of what it is it needs to be filtered off but unfortunately this can be a little annoying a lot of the particle sizes are really small so they easily slip past the filter paper what I ended up doing was an initial filtration through the coffee filter to get rid of the larger particles and then a secondary filtration to get rid of the smaller ones for the second filter ation I use a little bit of sea light and the solution that passes through is crystal-clear it was pretty slow though and I think it took two to three hours to filter everything anyway once everything passes through I wash the flask and the funnel with a little bit of water when this is done it's time for the fun part when I get to evaporate all of this water I poured it into a dish and now it's just a waiting game over the course of about a week I got some decent crystal formation but I felt like they were clumping up a little bit too much so as carefully as I could I tried to spread them out the problem with doing this though is you inevitably break off small little pieces these pieces might be so small that you can't even see them but they can serve as sites for new crystals to form this is a problem because it means as the lead acetate falls out of solution it will start growing on these small particles instead of building up the larger crystals I left it out for about a day or so and you can see a light dusting starting to form at the bottom to fix this problem I filtered everything through a coffee filter and then I transferred over my biggest and nicest crystals in the dish I was left with this mess I let it all dry over the course of a couple days and then I scraped it all off and transferred it to a plastic bag so coming back to my main crystal batch they've clearly grown in size but because I moved them around again I ran into the same problem so I repeated the process again where I filtered everything off and transferred the large crystals I had to repeat this a couple times until I got to this point where I was pretty much done there was only a small amount of liquid left so I picked out all my crystals and just evaporated the rest after letting them dry a little bit further this is what I had in the end unlike the other method where I got a hundred percent yield I only got 89 percent here I think the yield is a little bit lower because all the lead didn't react but I'm not exactly sure why because the crystals were so much bigger in this case the parallelogram structure is a lot easier to see I also formed a much bigger cluster this time and in my opinion it was also a lot nicer out of all of them though I think this was my favorite one where it was two crystals growing through one another anyway the final demo is to show you guys how it can be used to detect hydrogen sulfide hydrogen sulfide is a very toxic gas and at first it's pretty smelly however it quickly desensitizes your sense of smell so you stop being able to detect it which can be pretty dangerous so if you're going to work with hydrogen sulfide it's pretty much mandatory to have some other detection system to set this up it's pretty easy I just make a solution of lead acetate dip in some paper and then let it dry if the paper is exposed to hydrogen sulfide the lead acetate will react with it and form lead sulfide which we can see anyway I think that's about it I hope you guys enjoyed the video and I'll see you on the next one a big thanks goes out to all of my supporters on patreon anyone who supports me will see my videos 24 hours before I posted to YouTube and they'll also be able to directly contact me anyone who supports me with $5 or more will also get their name at the end of the video like you see here [Music]

Channel: NileRed

Views: 850,753

Rating: 4.9345832 out of 5

Keywords: lead, acetate, sugar, romans, port, wine

Id: lOjLuJyMmUQ

Length: 16min 31sec (991 seconds)

Published: Wed Jun 28 2017

Reddit Comments

[u/dtagliaferri]

and here is a list of people who have died from consuming it since it is sweet
https://en.wikipedia.org/wiki/Lead(II)_acetate#Resultant_deaths)