Sciencemadness Discussion Board

Extract BOTH nitrogens from urea?

fusso - 27-1-2021 at 17:19

I have a lot of urea but i need a lot of NH4 salts so i wanna convert the urea to NH4 salts. I know 1 of the urea N can be easily converted to NH4+, but how easy is converting the other N to also NH4+?

[Edited on 210128 by fusso]

symboom - 27-1-2021 at 17:33

I don't see how that could be done in a one pot way the only way I can think of is heating urea till it breaks apart to ammonia and carbon dioxide then condensing it to form ammonium carbonate.
Reacting urea with sodium hydroxide and leading the ammonia into an acid would be the other way

B(a)P - 27-1-2021 at 17:44

Why not add the urea to sodium hydroxide then capture the ammonia gas in water to form ammonium hydroxide?
You can then react ammonium hydroxide to form your salts.

fusso - 27-1-2021 at 18:04

Quote: Originally posted by B(a)P  
Why not add the urea to sodium hydroxide then capture the ammonia gas in water to form ammonium hydroxide?
You can then react ammonium hydroxide to form your salts.
But can this extract the OTHER N from the urea?

B(a)P - 27-1-2021 at 18:32

Quote: Originally posted by fusso  
Quote: Originally posted by B(a)P  
Why not add the urea to sodium hydroxide then capture the ammonia gas in water to form ammonium hydroxide?
You can then react ammonium hydroxide to form your salts.
But can this extract the OTHER N from the urea?


Isn't the reaction as follows?
NH2CONH2 + 2NaOH -> 2NH3 + Na2CO3

fusso - 27-1-2021 at 18:51

Quote: Originally posted by B(a)P  
Quote: Originally posted by fusso  
Quote: Originally posted by B(a)P  
Why not add the urea to sodium hydroxide then capture the ammonia gas in water to form ammonium hydroxide?
You can then react ammonium hydroxide to form your salts.
But can this extract the OTHER N from the urea?


Isn't the reaction as follows?
NH2CONH2 + 2NaOH -> 2NH3 + Na2CO3
Oh i thought it'd stop at cyanate.

Boffis - 28-1-2021 at 05:37

If you want it to stop at cyanate you need less alkali.

fusso - 28-1-2021 at 19:38

In the wiki page for isocyanic acid it said 'isocyanic acid hydrolyses to carbon dioxide and ammonia' but didnt state the rxn conditions, does anyone know what conds are needed?