Sciencemadness Discussion Board

ammonium acetate

paccman278 - 10-12-2004 at 02:16

cant seem to find a writeup for ammonium acetate.searched google and came up nothing, does any one have a copy of a write up. swip thanks you.

chemoleo - 10-12-2004 at 07:03

What's the problem with it? What would you like to know? Writeup? How to make it?

Ref: Synthesis of benzylchloride

solo - 10-12-2004 at 09:10

You might have better luck looking under more common names......solo

Ammonium acetate [631-61-8]
Synonyms: Acetic acid, ammonium salt; Ammonium acetate; Ammonium acetate ; AMMONIUM ACETATE, REAGENT (ACS);

kclo4 - 1-1-2005 at 17:31

Hares an msds
http://www.jtbaker.com/msds/englishhtml/a5508.htm
I found thousands for AMMONIUM ACETATE!!!!

are you searching on google

:P

Kalle anka - 23-6-2005 at 03:22

Yesterday i mixed ammonium hydrogen carbonate with an 30% aqueous solution of acetic acid until pH = 7. When the reaction subsided i tried to remove the water by heating the mixture but indeed, this does not work because the ammonium acetate decomposes. Then i tried to remove the water by heating the mixture under vaccum from the water aspirator. And finally to just let a small amount of it stay out in the sun on a black disc. Either way, nothing happened.

My question is whether it is possible or not to dry the ammonium acetate by any means when it is made this way.

Another possibility would be to react dry ammonia gas with anhydrous glacial acetic acid, but as seen, this is much more complicated.

Esplosivo - 23-6-2005 at 04:47

Not working?! Strange... I think you are trying to heat it more than enough to remove the water, therefore leading to decomposition.

Try removing 1/3 (or more) of the volume of the reactants, cooling and filtering the crystals formed. Place this in a dessicator (with CaCl2 dessicant) and the job should be done. Hope this helps.

Kalle anka - 23-6-2005 at 09:33

Thanks esplosivo! I have a heap of CaCl2, but unfortunately it's partially hydrated so i will have to bake it in the oven first and i'll try it.

Whats strange with this procedure of mine is that the liquid slowly turns to a syrup when more of the water is removed, and finally it decomposes quite fast and leaves nothing (!). My first idea was to get crystalline hydrated ammonium acetate and then dry it over CaCl2. Anyway, i don't know if i have over-heated the mixture because even under vacuum, the liquid slowly turned inte syrup. Do you know why this happens? partial decomposition, or is ammonium acetate just so damn hygroscopic that it wont crystallise out? I tried to cool the vacuumed-off liquid syrup in an ice-bath but nothing really happened. Strange


EDIT: Actually even under vacuum from the water pump at full blast (water boiling fine at 30 deg C with my setup) the liquid is warmed well over 70 deg centigrade (same vacuum) and it boils slower and slower until the boil almost ceased and left me that damn syrup, no crystals whatsoever

[Edited on 23-6-2005 by Kalle anka]

Lambda - 23-6-2005 at 10:14

Kalle anka, the crystals are damn hygroscopic. And Ammonium acetate does decompose, when tryining to dry-heat it.

Ammonium acetate is only slightly soluble in acetone. It has a 1:1 solubility ratio in water. So here you go...., and then to the drying methode of Esplosivo.

I have not checked this refference out yet:

Preperation from Acidic acid and NH3:
Zuffanti, J. Am. Chem. Soc. 63, 3123 (1941).

S.C. Wack - 23-6-2005 at 12:00

I'm not sure that using less-than-glacial acetic acid is practical. Perhaps a way that this could work is if excess ammonium carbonate was added, so that as ammonia is lost with the water, it is replaced. Obviously there are problems with this, and it would require that water is removed faster than the ammonia. I would think that an atmosphere/capillary of dry ammonia would be the preferred environment for drying.

Kirk-Othmer:
"Isolation of dry, normal ammonium acetate, prepared by neutralizing acetic acid with anhydrous ammonia or ammonium carbonate, is difficult because of ammonia loss during evaporation of water. Consequently, commercial grades of ammonium acetate are often mixtures of the neutral and acid salts, or are supplied as ammonium acetate solution."

Kalle anka - 24-6-2005 at 00:30

I tried to pour some of my ammonium acetate solution in acetone, although it is miscible with water in all proportions as you said Lambda, when a salt changes the density of the water, acetone is unable to mix with water any longer. That happened now, and the solution forms a stupid bubble underneath the acetone layer.

I decanted off the acetone and instead added 50% acetic acid, and then added the ammonium hydrogen carbonate. The reaction fizzes slower and less than usual, but in the end I wound up with that same stupid blob under the acetone (see attachment).

When I get the time to dry my CaCl2, I will first dry acetone with it and mix this with dried glacial acetic acid, and simply try to bubble anhydrous ammonia through this solution. Hopefully the acetate will fall out as the acetic acid reacts with the ammonia. Any thoughts on this one?

P1010026.JPG - 294kB

Lambda - 24-6-2005 at 03:23

I am sorry about this Kalle Anka, it was just an idee. Nice and interesting photo by the way !

Did you manage to get hold of:

Preperation from Acidic acid and NH3:
Zuffanti, J. Am. Chem. Soc. 63, 3123 (1941).

The author of this artical aught to have run into the same problem of drying the salt.

Kalle anka - 24-6-2005 at 04:21

No, unfortunately I don't have access to any of the articles in the publications of american chemistry society :( No, still have to thank you Lambda and you other guys. I will try the method with glacial acid in acetone because I just have the feeling it's a viable method. When I'll get the time to do it I will post results, but any comments and thoughts are truly welcome as making anhydrous salts like this for instance is a really important aspect of (organic) chemistry

Sandmeyer - 24-6-2005 at 13:10

i can get the JACS paper, but then what. Kalle, how did you upload that attachement in your post above? This stupid feature simply refuses to work for me, it only worked one time...

Extract from: Zuffanti, J. Am. Chem. Soc. 63, 3123 (1941)

Lambda - 24-6-2005 at 13:16

Dear Kalle Anka, this is all the relavant information I could find from the artical:
Zuffanti, J. Am. Chem. Soc. 63, 3123 (1941).

Experimental:

Materials.- Formic and acetic acids were made anhydrous by the methods of Kendall and Gross (6). All the other acids used were purchased from Eastman Kodak Co. and were made anhydrous by fractional crystallization and distillation under anhydrous conditions until the proper freezing points were obtained.

Apparatus.- The apparatus consists of three 10-cm. U-tubes connected in series. The center U-tube is used as the reaction chamber, while the other two U-tubes are filled with barium oxide and serve as drying tubes. The end U-tube is connected to a bubbler, containing a few cubic centimeters of concentrated ammonium hydroxide, which serves to indicate the rate of flow of the ammonia gas. The center U-tube is immersed in a glycerol-bath to obtain uniform heating. Two thermometers are used to obtain the temperature inside (t1) and outside (t*) of the reaction chamber.

Preparation of the Anhydrous Ammonium Salts.- Ammonia gas is allowed to sweep out the system for approximately eighteen minutes. A small amount (about 0.5 cc.) of the anhydrous carboxylic acid is sprayed down the wall of the center U-tube using a medicine dropper with a restricted opening. A thin layer of white crystals of the ammonium salt immediately forms on the wall of the Utube. The flow of gas is continued at the rate of approximately one bubble per second for a half hour or until the reaction appears to be complete, before starting the melting.

(6) Kendall and Gross, THIS JOURNAL 43, 1431 (1921).
(?) Belcher, ibid., 69, 2744 (1938).

Not much, but this may have saved you some time, if you would have put your hopes on this article. I am still at the job, so....who knows what we and others may come up with.

Your idee about dissolving anhydrouse acetic acid in aceton, and then bubbeling dry ammonia gas through it, sounds promising though.
Quote:
If many minds are focust on a problem, eventually a solution will be found.


[Edited on 24-6-2005 by Lambda]

S.C. Wack - 24-6-2005 at 15:54

FWIW, these are the entries for the ammonium formates and acetates in the 1936 edition of Gmelin's Handbuch.

Attachment: gmelins_23_388_400_1936.pdf (366kB)
This file has been downloaded 2388 times

Kalle anka - 24-6-2005 at 16:01

Thanks guys, especially Lambda for your greatly appreciated investment of efforts, this is an unvaluable starting point to making anhydrous ammonium acetate and similar salts. I will try the method slightly adapted since i dont have u-tubes :P

The reason why i thought of adding ammonia to anhydrous acetic acid in acetone is that this solution can be used in my apparatus and for another reason: I have a RBF and a gas inlet tube that fits accurately into the solution through a claisen at the top. That way i can use a chlorcalcium tube on the second port of the claisen and use a magnetic stirrer to disperse gas evenly into solution, but, at a second thought, this can be considered gross overkill as reacting the dry glacial acetic acid with dry NH3 is actually enough.

But still, consider you want to make a larger amount of the salt, say 5g ammonium acetate or even more, then spraying a mist of the acid can be cumbersome considered the quantity (really thin mist). At first I supposed this wouldn't be ideal since ammonium acetate can possibly make a crust that prevents full reaction of ammonia and acid, and result in acid salt. ( Remember you cannot just open the reaction vessel and crush crust whenever it forms when working with very near to anhydrous conditions.. :( ) But who knows, the guys in the article did it that way..

When in solution, the acetic acid is always dissolved, and as soon as ammonium acetate is formed, it precipitates owing to its relative insolubility and this would therefore lead to the neutral salt when this precipitate (no idea how it looks like) was filtered, rinsed with dry acetone and then dried under vacuum.

Still this is only theoretical to this point, i will need to try it to subsequtnly be able to tell whether it works or not..


Sandmeyer: i used that "browse box" under the textbox where you add the text of your post. Simply browse for your file and open it. then it will follow the post as an attachment, took me some time though to upload it. Can take a while when this uploads and you get a blank screen until it's finished.

Kalle anka - 24-6-2005 at 16:13

WOW S.C. Wack!! I saw now that you posted a reply shortly before i completed my last reply. In this article on the page 6 of 13 it explicitly says that one can get anhydrous neutral ammonium acetate by flowing dry ammonia through an ethereal solution of glacial acetic acid! Seems my method really would work. I will try it as soon as I possibly can. The slightly higher solubility of the salt in acetone than in the somewhat lower polare ether wouldn't seem to be a problem though, and acetone is easier to use than ether but I can try both methods.

akcapr - 25-6-2005 at 12:08

"Ammonium acetate [631-61-8]
Synonyms: Acetic acid"

so ammonium acetate is hte same thing as acetic acid?

The_Davster - 25-6-2005 at 15:33

No. What was the source of that quote akcapr?

akcapr - 25-6-2005 at 15:40

the third post down from the top

The_Davster - 25-6-2005 at 15:47

Quote:
Originally posted by solo

Ammonium acetate [631-61-8]
Synonyms: Acetic acid, ammonium salt;


Note that is "acetic acid, ammonium salt", not just "acetic acid" that is, the salt formed by the reaction of acetic acid and ammonia.

Read closer;)

Jettin4u - 1-7-2005 at 07:41

I have made ammonium acetate using ammonium carbonate and acetic acid. then filtering and recrystalizing. if you are trying to use this to make an acetate you can just use the solution of ammonium acetate. depending on what you are doing with it

Easy anhydrous ammonium acetate using Ziplock bags.

Tacho - 7-9-2005 at 05:06

I made anhydrous ammonium acetate rather easily. Fist I made NH3 gas in a ziplock bag, as described here putting 1 small spoon of NaOH and 1 small spoon of ammonium chloride in the bag. Lock the bag, remove as much air as you can and mix both with your fingers (your fingers outside the bag, chemicals inside the bag, of course). You can hear the fizz as the they react and the bag inflates. Carefull! Ammonia hurts and kills.

Then I put about 2ml of glacial acetic acid in a syinge, connected it to the bag and started a push-pull movement of the plunger so that ammonia gas goes in and out of the syringe (hold the syringe so that the tip points up and the acid stays inside the syringe all the time). The acid got hot, and after about five minutes (you have to keep the "in and out" movement all the time to recirculate the ammonia gas) crystals begun to form. Eventually, the whole thing was crystalized.

When you think all acid has reacted, remove the plunger and use a spatula to get the crystals.

Maja - 14-5-2006 at 08:43

I have made Ammonium Acetate by bubbling NH3 into GAA. I didn't dried NH3, because i thought that very little ammount of water did not interrupt crystalization of ammonium acetate. Poured into 250ml graduated cylinder 150ml of GAA and started to bubble wet NH3 from sodium hydroxide and ammonium nitrate. Stopped when pH was more than 7. Poured all mass into plastic box with lid(from sandwiches and other things... air tight) and let it cool(Ammonium acetate actually melted during reaction and it was quite HOT!) after all mass crystalized I grinded it and putted into desiccator with anhydrous MgSO4. After a few days I will check it if it's not dry I will obtain some CaCl2 and dry over it ... Will report.

leu - 15-5-2006 at 05:15

You cannot heat ammonium acetate to more than 60 degrees Celsius under a vacuum, a post from long ago:

According to Thermoanalytical Properties of Analytical-Grade Reagents-Ammonium Salts; Talanta, 11(6), 913-40 (1964), ammonium acetate's differential thermal analysis peaks are: 100, 115 and 155 degrees, and the derivative thermal gravimetry peak is 150 degrees, thus it can be dried between the temperatures of 30 to 40 degrees Centrigrade without decomposition. It's endothermic. Probably the best procedure would be to do as suggested (silica gel is certainly the best general purpose dessicant, due to availability/inertness/easy recyclibity), between 30 and 40 degrees Centrigrade, and if using a dessicator instead of flask/container, then a dry box (transparent plastic bag set into a cut out cardboard box, using duct tape to attach rubber gloves into holes cut into the bag and the bag to the box; dessicant container within box) to open up the dessicator/dry reagent container and handle and measure and the dry reagent, and dissolve it into a solvent if needed.

You can make an inexpensive dessicator suitable for this from a glass block normally used for construction by drilling a hole in it:

To Drill Holes in Glass

By taking a good steel drill and wetting with a saturated solution of camphor in oil of turpentine, holes may be rapidly and easily drilled through the thickest plate glass.

AreteVeteran - 18-5-2006 at 19:53

cant you just subsitute ammonia for sodium bicarb in a reaction with acetic acid?

NaHCO3 + CH3COOH ----> CH3COONa + H2CO3

so NH3 + CH3COOH ------> CH3COONH4

there ya go
find yourself some vinegar and ammonia if you cant get better grade chems and react away
the only other product is water which is also a reactant

~Arete

Maja - 21-5-2006 at 02:42

What is your point to make Sodium acetate ? I don't get it.