Sciencemadness Discussion Board

Purifying this store bought ammonia

sargent1015 - 7-10-2012 at 16:31

Hey guys, I recently bought some shurefine ammonia, unfortunately, it says sudsy on it. But, it was cheap and I didn't really think it would be a huge problem to get out.

My test was to add some to some copper sulfate and get the complex. To my surprise, I got the dark blue complex and a light blue solid. I am thinking that the "sudsy part" is nothing more than Na2CO3 and I just made copper carbonate. This makes sense since, after I stirred the mixture, it all reacted and I lost the pretty blue.

Now, the MSDS is not online and I am waiting for an email from the producer, but does anyone have ideas on how to get rid of the "sudsy" part? I like that this product was .99 for 2 quarts, but it is ridiculous if the contaminant is what I think.

Thanks guys for the replies!

DougTheMapper - 7-10-2012 at 16:53

Heating the solution will drive off the ammonia. Bubble the gas into cold distilled water to make whatever concentration you wish.

Ammonia solubility in water:

47% (0 °C)
31% (25 °C)
28% (50 °C)

Ideally use a fritted sparging tube. Alternatively a vigorously magnetically-stirred flask of ice-cold water should do the trick for anything up to 15-ish percent.

sargent1015 - 7-10-2012 at 17:11

Hmmm, I'll give it a shot!

DougTheMapper - 7-10-2012 at 17:35

Depending on the concentration you need, you can also seal two beakers in a plastic bag, one with distilled water and the other with ammonia solution. Eventually they will equalize in ammonia concentration, one pure and the other with the suds in it. Keep in mind that the end result will be of a little less than half of the original concentration.

This works for pretty much all aqueous dissolved gas solutions like HCl, formaldehyde, methylamine, etc.

[Edited on 8-10-2012 by DougTheMapper]

sargent1015 - 7-10-2012 at 17:45

That sounds substantially easier (life of a college student), So I'll for sure give that a try

Funkerman23 - 7-10-2012 at 18:29

I was going to say.. Doug's method is a whole lot easier to do than hunt fritted sparging tubes with 24/40 heads..believe me I've been trying for a good while now.

Oscilllator - 8-10-2012 at 00:47

It just so happend that I purified the same "sudsy" ammonia myself recently.
The way I did it was to fill a 500ml Erlenmeyer flask to around the 300ml mark with this ammonia, stopper the top and then run a hose out from that little nozzle in the side.
The hose fed through to the bottom of a very tall, very thin glass jar (the taller and thinner the better). My jar was a fancy jar for holding olive oil and it has a bottom diameter of about 45mm, a height of around 300mm and a top diameter of about 20mm. A tall measuring cylinder would work well too, though.
Anyway, the jar was filled with ice-cold water and was sitting in a bigger jar also full of cold water, with extra ice cubes :)
So what you do is heat up the sudsy ammonia until it is boiling. This drives off the ammonia because the solubility of gasses decrease as the temperature increases. The ammonia gas, along with a small amount of water is bubbled through the cold water to re-dissolve it. I dont know how concentrated the ammonia is but when I smelt it it nearly burn my nose off, so it cant be that dilute.
The solution of ammonia you get of is perfectly clear, and much purer than anything you would get via reacting all the soap away. The process isn't that efficient, but like you said the sudsy ammonia is very cheap.

Also the MSDS of "cloudy ammonia" which is the exact same stuff as "sudsy ammonia" can be found here:
http://www.cleanwithsupreme.com.au/download/Cloudy%20Ammonia...

borrowedlawyer - 8-10-2012 at 02:54

Quote: Originally posted by Oscilllator  
It just so happend that I purified the same "sudsy" ammonia myself recently.
The way I did it was to fill a 500ml Erlenmeyer flask to around the 300ml mark with this ammonia, stopper the top and then run a hose out from that little nozzle in the side.
The hose fed through to the bottom of a very tall, very thin glass jar (the taller and thinner the better). My jar was a fancy jar for holding olive oil and it has a bottom diameter of about 45mm, a height of around 300mm and a top diameter of about 20mm. A tall measuring cylinder would work well too, though.
Anyway, the jar was filled with ice-cold water and was sitting in a bigger jar also full of cold water, with extra ice cubes :)
So what you do is heat up the sudsy ammonia until it is boiling. This drives off the ammonia because the solubility of gasses decrease as the temperature increases. The ammonia gas, along with a small amount of water is bubbled through the cold water to re-dissolve it. I dont know how concentrated the ammonia is but when I smelt it it nearly burn my nose off, so it cant be that dilute.
The solution of ammonia you get of is perfectly clear, and much purer than anything you would get via reacting all the soap away. The process isn't that efficient, but like you said the sudsy ammonia is very cheap.

Also the MSDS of "cloudy ammonia" which is the exact same stuff as "sudsy ammonia" can be found here:
http://www.cleanwithsupreme.com.au/download/Cloudy%20Ammonia...


I pretty much did that exact same procedure, however I am not sure I am getting that much ammonia to go in to solution, as I forgot an ice bath. I will try and redo it after I titrate with sulfuric acid.

[Edited on 8-10-2012 by borrowedlawyer]

Oscilllator - 8-10-2012 at 21:10

Yeah the ice bath is very important, because ammonia is much more soluble at lower temperatures, and the gas being bubbled through is hot, so you'll end up heating up the water and thus getting a very weak solution.

unionised - 9-10-2012 at 11:44

If the cloudy stuff was sodium carbonate, it would dissolve to give a clear solution.
I suspect it's soap.
Copper soaps are not soluble in water so you would get a blueish precipitate.

sargent1015 - 9-10-2012 at 13:55

Will copper soaps dissolve in acid? I tested this with a little HCl and it dissolved outright, didn't seem to be any evolution of gas

elementcollector1 - 3-12-2012 at 19:04

Would a 100mL graduated cylinder be a good container for the resulting ammonia solution?
Also, if you use the same volume of cold, distilled water as ammonia, would you get the same concentration, within reason?

sargent1015 - 3-12-2012 at 20:08

They would equilibrate at half the initial concentration of the ammonia I believe. I wouldn't use a grad cylinder just due to the odor, unless you have some parafilm or stopper to dedicate to the task

elementcollector1 - 3-12-2012 at 21:18

So, if I use half the amount of cold, distilled water, I should obtain a smaller amount of equal concentration of ammonia. No idea if that's right, but it sounds right.

UnintentionalChaos - 3-12-2012 at 21:39

Quote: Originally posted by unionised  
If the cloudy stuff was sodium carbonate, it would dissolve to give a clear solution.
I suspect it's soap.
Copper soaps are not soluble in water so you would get a blueish precipitate.


Except they would just re-solvate as tetraamine carboxylate. Assuming it's a carboxylate "soap" and not a chelating agent or sulfonate sulfactacant...or both.

Sedit - 3-12-2012 at 23:14

I doubt it's a carbonate as it sounds more like a stearic acid or some other soap. Try adding Mg ions to the solution to see if the soap precipitates out.

elementcollector1 - 3-1-2013 at 13:04

Any advice for bubbling a gas into water? I've had suckback problems, even with that inverted funnel trick.

Pyro - 3-1-2013 at 13:10

don't submerge the funnel too much.

MrHomeScientist - 3-1-2013 at 13:20

I have a nice gas washing bottle that I've tried to use in a very similar experiment, but I've had suckback problems with that as well. Barring the inverted funnel trick (I want to use my glassware otherwise I admit the purchase was unnecessary!), any tips on preventing suckback in such a setup?

My ammonia gas generator was an RBF that led to a vacuum takeoff adapter and a smaller RBF (to catch suckback), and the takeoff was led to the input of the gas bottle. Pretty much as soon as ammonia started to evolve there was immediate suckback to fill the little RBF. :mad:

elementcollector1 - 3-1-2013 at 13:25

Trying to visualize your setup... failing miserably.
I think suckback has to do with the bubbler itself, it creates a vacuum thus sucking up the water and such. Which is why glass fritted disks are apparently gold in this situation.
Anyway, what about concentration by freezing, analogous to hydrogen peroxide?

MrHomeScientist - 3-1-2013 at 13:48

This is the gas wash bottle I'm talking about :


The gas goes in the inlet on the left and bubbles up through the glass frit at the bottom. The idea was to pass in ammonia gas and dissolve it in the water in this bottle. The gas was generated in a ground-glass type setup that had a large RBF as the reaction flask, with a smaller RBF in between that and the wash bottle to catch potential suckback. The whole system was ground glass, and so was sealed up until the outlet of the wash bottle which was open to the atmosphere. Hope that makes a little more sense.

Hexavalent - 3-1-2013 at 13:55

Damn, I wish I had one of those! Where did you obtain yours?

Pyro - 3-1-2013 at 14:00

http://www.hinmeijer.nl/product/46938/Gaswasflessen.aspx
there you go

elementcollector1 - 3-1-2013 at 16:08

This is my setup, it's not perfect but it seems to work.



Normally the funnel would be inverted into a beaker, but you get the idea.

MrHomeScientist - 4-1-2013 at 06:26

Hexavalent, I got that bottle from good old Dr. Bob. I think it was one of his last ones, but it'd be worth a try to ask him if he has more!

shannon dove - 5-1-2013 at 08:20

Quote: Originally posted by DougTheMapper  
Depending on the concentration you need, you can also seal two beakers in a plastic bag, one with distilled water and the other with ammonia solution. Eventually they will equalize in ammonia concentration, one pure and the other with the suds in it. Keep in mind that the end result will be of a little less than half of the original concentration.

This works for pretty much all aqueous dissolved gas solutions like HCl, formaldehyde, methylamine, etc.

[Edited on 8-10-2012 by DougTheMapper]

What about setting a third container in there with calcium oxide in it. Would that bring the concentration up?

S.C. Wack - 5-1-2013 at 15:12

The water container might work better with some sulfuric or phosphoric acid added to it. Or HCl, with a wide glass tube connecting the HCl to a wide container of crap ammonia.

shannon dove - 5-1-2013 at 16:43

Quote: Originally posted by S.C. Wack  
The water container might work better with some sulfuric or phosphoric acid added to it. Or HCl, with a wide glass tube connecting the HCl to a wide container of crap ammonia.

I thought the idea was to make an ammonia -water solution, not an ammonium salt.

S.C. Wack - 5-1-2013 at 18:06

Quote: Originally posted by shannon dove  
I thought the idea was to make an ammonia -water solution


Sure is! That's why I've put y'all on the most practical route to it! (without distilling it). There's only one practical way to make these soapy and/or weak ammonias useful.

[Edited on 6-1-2013 by S.C. Wack]

elementcollector1 - 5-1-2013 at 18:20

Can you distill an ammonium solution?

S.C. Wack - 5-1-2013 at 19:14

Quote: Originally posted by elementcollector1  
Can you distill an ammonium solution?


Why not? Don't expect anything but water to come over...unless you add NaOH first...

[Edited on 6-1-2013 by S.C. Wack]

elementcollector1 - 5-1-2013 at 19:31

So, will distillation remove water, leaving the starting solution more concentrated?

S.C. Wack - 5-1-2013 at 19:41

Quote: Originally posted by elementcollector1  
So, will distillation remove water, leaving the starting solution more concentrated?


If the salt is one of a strong acid...it will fail with weak acids.

shannon dove - 5-1-2013 at 20:03

Oh, I see, make an ammonium salt, boil the water away, then react the dry salt with a strong alkali like sodium hydroxide (dry) then use this anhydrous ammonia gas to mix with your very own clean water to whatever concentration you want.
Is that the idea?

S.C. Wack - 5-1-2013 at 20:19

In this case it would be preferable to separate the soap and ammonia (in whatever form) at the same time like I said but 2nd choice would be isolating the salt from the soap by partial evaporation and recrystallization because you might find fragrance or etc weirdness from distilling the soap with caustic.

PS The problem is that although distilling concentrated ammonia solutions works great for getting ammonia out, it really sucks for weak solutions, unless you only want weak solutions.

[Edited on 6-1-2013 by S.C. Wack]

elementcollector1 - 5-1-2013 at 21:38

Sounds like a better plan than mine. How 'bout ammonium chloride?

S.C. Wack - 6-1-2013 at 09:14

Vapor phase reaction at STP with HCl would be best, if it works with these dilute solutions and the salt condenses. Unless you want ammonia now.

If you neutralize (not to pH 7) grocery store ammonia with HCl, you're going to be boiling off a lot of water, and you have to really boil off a lot of water to get enough ammonium salt to be worthwhile. Soaps start precipitating at a point. Although that could be a pure one-day stovetop adventure, I'd look into battery acid and vapor.

elementcollector1 - 7-1-2013 at 10:05

So, in other words, boil both ammonia and HCl into a flask, and let the reaction sort itself out. At the end, there should be a deposit of ammonium chloride (hydrate? Anhydrous?)

Do you think concentrated sulfuric acid would work better in solution, as the sulfuric will steal water from the ammonia?