Purifying OTC Chemicals: Simple Distillation

[98JMA]

Unless you are certain that your product will come over first, never plug the receiver vessel in securely . . .if something else comes over at a lower temp. then it will be a right pain in the arse to get the flask off quick and install a new one for your pure product.

Always throw away the first 20ml or so of a distillation as it may be impure, having come through the apparatus first. Once it has come over, the system has been flushed with the purified product and it is suitable to collect.

[AlChemicalLife]

hey can u come to my school. it would be vary cool for the science brothers to come to my school.iv ben wanting pepole to see what chemistry is all about and how fun it is. and it would be cool to meat u guys too :) . thx if u can do it i can send u a website url to my school.

thx

Alchemicallife

[mcwario13]

watch?v=4T0-b1QQ0ek&feature=g-­all-lik&context=G28abf4aFAAAAA­AAAQAA is that you?

[mrhomescientist]

@mcwario13 It is! That's part of a science outreach program I do to get kids interested in science and technology careers. That's funny you found it :)

[michalchik]

You distillation would be even more efficient if you added a little hydrogen peroxide and sulphuric acid ;-).

On the serious side, you should mention that using fresh acetone is important to avoid concentrating peroxides. Otherwise great video.

[domvasta]

you can get rid of the 2-3% water by drying with CaCl2 or MgSO4

[98JMA]

@domvasta

Yes.

[watchmefall555]

Where did you get your evaporating dish and the dish with the cold water bath? I cannot find any glassware that is wide enough to create a bath for my 1000mL rb flask, outside of a 3000mL beaker that is. the only problem with using a 3000mL beaker is that if I am using an oil bath it takes way too much mineral oil to be economical.

[homealchemy]

You definitely need a way to diffuse pressure... Invest in a vacuum adapter! Other than that, love your videos.

[neosback47]

where did you learn all this, a chemistry class or something??

[aten747]

THANK YOU! ive been trying to do this for a while but i don't have good enough lab ware

[mcwario13]

next video on reflux

[mrhomescientist]

@mcwario13 Maybe! I've done it once or twice before, and it's very similar glassware. Thanks for the suggestion.

[TheCaphits]

Wouldn't you want the thermometer very very close to the actual boiling liquid? Maybe even in it?

[mrhomescientist]

@TheCaphits No because you want to measure the temperature of the vapor. That way as long as the temperature stays at the boiling point of the liquid you want, you know that is the only component in the vapor. Once it starts rising, you're starting to get other higher-boiling reagents coming over and contaminating your product. I think in the boiling liquid wouldn't give you as much information, or wouldn't be as accurate for this setup as reading the vapor.

[nickbhalo]

I'd love to have a distillation set up like this, but all I can afford is the United Nuclear one.

[fegolem]

I had some old Sodium Acetate hand warmers and tried to melt the crystals in boiling water so that I could use them. Turns out the pouches had holes in them and the solution leaked into the water bath. The water bath was well water that probably has minerals and some large particles in it. By what methods can I purify the polluted Sodium acetate solution back to a usable "hand warmer" concentration. It won't stay in solution. Possibly contaminates acting as seed crystals?

[mrhomescientist]

@fegolem Recrystallization is the way to go for something like that. That was actually going to be my next video in this series! The general idea is to evaporate your solution down most, but not all, of the way until crystals start forming upon the solution cooling. Impurities get concentrated in the liquid, and your sodium acetate should crystallize into fairly pure product. Just decant the leftover liquid. Stay tuned for the video!

[MrLol333]

Can you say where i can get this stir plate and how much does it cost ?

[TheJamiemilner]

great video!

could you do a video on separating chemicals of differing solubility in a given solvent.

thanks

[mrhomescientist]

@TheJamiemilner Yeah that would be a good one for this series. My next planned video for it was recrystallization, which is a very similar process to what you describe. Stay tuned!

[99Chemicals]

Do you have a vacuum take-off adapter? It would seem like a good idea to use it so you can release pressure.

[hawk1buster]

This a real fine discription...... scientist to redneck translation. Your not teaching college students.

[NoromiEnki]

My only concern is that the setup doesn't have any outlet to relieve sudden increases of pressure. In this case, since there's no grease on the joints, it might escape around the joints, or force out the one joint that isn't Keck clipper, your thermometer. In general, though, it's a good idea to include a 105 degree vacuum take-off adapter at the end between the condenser and receiving flask.

I'm not hating, just a tip to keep things safe for the future.

Love the videos, keep it up man!

[knglaser]

@NoromiEnki I second that. Most gasses escape early in the distillation and they could easily make a mess of the setup. The vacuum adapter also makes it very easy to lead out any gas to the outside.

[mrhomescientist]

@NoromiEnki Thanks, those are very good points. I actually do have that adapter, just didn't use it for fear of losing product. But now that I think about it, all vapors should have condensed by then anyway so it really is just a safety feature. Every time's a learning experience, and I'll remember that for the future. Thanks for the input!

[98JMA]

@mrhomescientist

If you really are worried about losing products, just put a long rubber tube onto the end of the pressure-release hole/tube on the 105* adapter and lead it into an open flask.

[aeroscope]

water does not form azeotrope with acetone.

[Ave210Knife]

Where do you get your labware?

[MossOwnsYou]

Mr. Science Beard returns!

[mrhomescientist]

@MossOwnsYou Heh yes, glad to be back! I've been very busy with two other big projects at home, and one will soon be finished for your viewing pleasure :)

[BorderCityBandit]

holy shit,the words being used are way over my head,can you have a scientist to redneck translation.its a cool video,but I cant replicate what I dont understand,lol

[mrhomescientist]

@BorderCityBandit Haha well the wikipedia article on distillation is pretty helpful. What don't you understand? I can try to explain it better.

[Chaoschemiker]

You could have refluxed the crude acetone with potassium permanganate, to avoid iso-propanol impurities, and distill the treated acetone afterwards.

[mrhomescientist]

@Chaoschemiker Good idea!

[LepomisCyanellus]

Nice demonstration.

Thank you for sharing.

[norxcontacts]

How pure is storebought acetone?

[mrhomescientist]

@norxcontacts That's actually a good question that I don't really have an answer for yet. All the MSDS's I've found so far list the contents as "100% acetone", but that's obviously incorrect since nothing is ever 100%. I'll get back with you if I find something different.

[TerminalRhinoVirus]

How much did those ground glass stoppers cost you?

[mrhomescientist]

@TerminalRhinoVirus All the pieces seen were about $100 total. I got a good deal from someone on a chemistry forum I'm a member of. eBay occasionally has some pretty nice distillation kits up for reasonable prices, too.