OTC Dichloromethane

hi everyone and welcome back to the lab in this video I'll be showing you how to get that chloromethane for things you can find at the hardware store and chloromethane has the formula ch2cl2 and can be represented by this structure here you notice that chlorines are an app size with because of course of their electronegativity which caused them to repel each other so you mostly sit in this sort of a state and that makes a molecule fairly nonpolar because it's nonpolar of course it does not dissolve in water and because if it's lightweight it doesn't have a very high boiling point so low boiling point doesn't dissolve in water makes a perfect extraction solvent so it's very popular in organic labs to extract things with dichloromethane since it can be easily removed from whatever you extracted because of its low boiling point and it's fairly in soluble in water the product you can find that chloromethane in is paint stripper usually paint strippers will either have dichloromethane or toluene yourself like that so you need to look at the back to make sure but this brand here this clean strip premium sprayable stripper happens to have dichloromethane in it and in fact you can verify this by even looking on the back or finding the MSDS on the back you can see here this contains methanol and methylene chloride is the trade name for dichloromethane is sort of an older name that they use and in fact if you bring up the MSDS for this stuff you'll find that it's 60 to 100 percent by weight chloromethane and 10 to 20 percent by weight methanol so also there is some polymeric goop in there which I'll get to in a minute that makes it sort of this sloppy gooey stuff so we're going to try today and distill the deckle or methane or isolate the dichloromethane from this paint stripper these two diagrams here represent the mixture of compounds will be distilling from the paint stripper the reason will be distilling first is because there's a bunch of polymer crap in the paint stripper and if we go to try and do an extraction or something like that on it the polymer is just going to get in the way it's going to dirty up the glassware and contaminate the product so the first order of business is to distill all set up for simple distillation and take these two products the methanol and the chloromethane off into a separate receiver after I do that we can go ahead and try and separate these two and that's pretty easy because you'll notice that chloromethane is fairly nonpolar right we have these two electronegative centres here on the side and they sort of balance each other out and make the molecule fairly neutral wares and methanol this lone pair of electrons on the oxygen creates a negative area over here and the hydrogen proton that's on a hydroxyl group creates a positive area over here and because the chain of carbons is so small that makes this molecule actually quite polar it's soluble in all proportions in water in fact and a chloromethane exhibits fairly limited solubility in water so we'll do is we'll mix this with water and all the methanol will go to the water layer right because the water is polar and attracted to it and the dead chloromethane being less polar will layer out after a couple of rinses like that we'll have removed substantially all the methanol from it and we can go ahead and just dry the TEC Laura methane over some muck some drying agents I think potassium carbonate should be suitable and then that we can go ahead and either redistill that or store it I think store is appropriate because that's in carbon e has pretty much zero solubility and nickel or methane so anyway let's get to the lab and dry it all right so the first step will be to load a bunch of the you paint stripper into this flask still a little wet from washing but that's not going to make a difference here I've got a one liter flask and my heating mantle here and we'll just go ahead and put a funnel on that and then I'll pour in some of this lovely goopy paint stripper and you can see what I mean by gloopy all right there we go you can see the flask is about half full with dichloromethane containing goop polymer and crap and I'll go ahead and set this up for simple distillation and we'll get that started all right so I've set it for simple distillation to see I've got here my 1 liter heating mantle with a jack underneath it I've got the flask with the pink stripper in it with a standard still had all 24 40 and this is a thermometer well we're not actually gonna take the temperature because it's not really going to tell us much there's really no point I have a 300 millimeter Liebig condenser ready to convince the dichloromethane and methanol vapors reason I chose 300 millimeters over my standard 200 is because Tecla or methane and methanol both have fairly low boiling points and the long condenser will help make sure the condensation process is efficient so anyway down here I've got a standard vacuum adapter remember never hit a closed system this is the opening in this particular system and a 500 milliliter collection flask for the mixture that we will be distilling over now I'm not going to distill this to dryness or anything I'm just going to distill it until it starts foaming or bubbling or looking like it might be hard to take out so this isn't going to be particularly you know we're out trying to get 100% yield out of this we're just trying to get chloromethane in a very easy way so that said let's turn the mantle on get the heating going and they should start boiling in a minute the pink stripper is not boiling and vapors are traveling through the head and into the condenser you can see we're using pretty much all of the condenser the vapor front does really stopped a lot halfway down and we are pulling off dichloromethane at a ridiculous pace right now that's actually a little faster than I want so I turned the heat down just slightly butts up will be stripping this pink

stripper in no time and more than 20 minutes for this one but see what happens here the end and it looks like the distillation is wrapping up that's getting awfully thick and I think it's going to be a bit difficult to get out of the flask so I'm going to go ahead and stop now besides I think that judging by the changed consistency of liquid condensing in the condenser you can kind of tell ever before it was sort of making beads and not sort of a continuous sheet that sort of indicates that that's probably methanol coming over rather than the chloromethane just sort of thing that experience tells you anyway so we're mostly done and you can see that the flask is pretty much full about three-quarters full it's about as far as you want to use these plats anyway so I'm gonna go ahead and stop the distillation turn off the heat and lower the mantle and for this cool sufficiently to stop distilling product we can go ahead with processing the mixture the pressure the distillation is approximately 400 milliliters of a very dense liquid and this is characteristic of a lot of chlorinated solvents they have very high density so this feels much heavier than it would be if it was water for instance of course this is a mixture of that chloromethane of methanol and will now proceed to wash the methanol out of it using this handy dandy set bottle heater so what I'm going to do essentially is just for the dichloromethane into the funnel and make sure these stopcock is closed right now sure mister you don't make that alright now I'll add a little bit of water and remember the water is going to act to absorb the methanol so get a good layer going on there that's about good and you can see the decorum I think is much heavier than the water and the water is now floating on top of the biphasic mixture there and the methanol is now rapidly being absorbed by the water so to help that along I am going to seal this up and shake it and the chloromethane has a fairly high vapor pressure so it tends to pull out Stoppers and things like that so you have to be very careful and make sure that we're shaking this you've been coughing now this is a special type of set funnel which happens to have a vent if you look here this little vent hole there and if I line up this Ridge in the stopcock with the vent hole I can vent it like that just by turning this a little bit rather than having to flip it upside down and vent it using the stopcock so I'm just going to go ahead and do that I can feel the pressure building up and we'll give that 102 to settle back out all right you can see the mixture is mostly settled the dichloromethane layer is a little cloudy because it's taken on some water but that will go away in a later step and now the methanol is located in the water layer so what we'll do is we'll just drain off the top layer or SART will drain off the bottom layer and keep that and then discard the top layer since it's just methanol and water there we go so here is the dichloromethane it is a little wet as you can see and we have our first wash of water which I will be putting in a chlorinated waste bin so we'll be emptying it into this separate container over here and now as the dead chloromethane back to the funnel course making sure the stopcock is closed and i'm just going to repeat this process two more times you can see that the second time the water layer is out much more quickly which indicates that this layer is now extremely hydrophobic and that's because we've washed most of the methyl off the first washing but this and one additional washing should separate it nearly so just shake this up maybe ii do all right this is the dichloromethane after the last wash and you can see that it's fairly pure they're just no methanol in it but it's got quite a bit of water and that's what's causing the cloudiness and also you can see there's some beads on the top here and that's just from that's artifacts from using the set funnel this fo will form a vortex near the end and things like that so we have a little bit of water in that but no fear it's easy to clean out we're going to do that with some technical grade potassium carbonate so all I'm gonna do is add a few spoonfuls of fancy carpet to this and I'll shake it up and it's almost like a magic trick where this will go from cloudy to clear in a couple of seconds so let's do that a couple of good spoonfuls and I can already see it's clarified but I wanted to show up close but you can

see actually now how much clearer it is already but I'm just going to shake this around again venting often get the potassium chloride first are the Edessa carbonate mixed in and you can see a sort of clumps up in the presence of water but we are very quickly removing the water from this dichloromethane as you can see it's becoming quite clear all right so here's the final product a about 350 milliliters of dried that chloromethane I'm just going to simply pour this into the storage bottle and I'm gonna be careful not to get any of the desiccant in there so here's the product of the evenings work it's about 350 milliliters of dichloromethane that is pure enough for you know 99% of the uses you'll need dichloromethane for further if you need dental or methods more pure than this you'd probably distill the stuff that you purchased anyway so there's really no sense in Reaper fighting this by distilling and all sorts of like that it's really just a waste of time so anyway if you like this video please press the like button if you'd like to donate a dollar or two to help me continue to make these videos I do a patreon account I'll put the description or I put the link in the description I don't get paid for all my videos note that this video didn't cost very much money so I'm not claiming any money on it but the videos I do make that I need help with paying for that is they'll cost me hundreds of dollars sometimes I do claim the money for so rest assured that you guys have been so cool to me I'm gonna be cool right back to you and I'm only going to claim money on cool videos however I do want to show some of the more basic stuff like this video so I'm going to make them anyway just not get paid for them so anyway if you like the video like I said to hit the like button subscribe if you want to see more I got a lot more videos coming and as always thanks very much for watching