[kingkurry]

I need to figure what reaction will occour when Ammonia is poured into a copper(II) nitrate solution. Yes, there is water present. Here is the equation i got, but i feel like i am wrong:  3Cu(NO3)2 + 4NH3OH -->  2Cu(OH)2 + Cu(NH3)4 + 3NO3

I think there is OH because the Ammonia is a base and by defenition would increase the concentration of OH- ions and the copper would naturally bond to these, but im not 100 % sure.

Also is it the  Cu(NH3)4 that makes the dark blue color, or is atleast a darker blue than Cu(NO3)2?

Also what exactly is Cu(NH3)4 called?

[AWK]

[Cu(H₂O)₄]²⁺ + 4NH₃ = [Cu(NH₃)₄]²⁺ + 4H₂O

[Schrödinger]

@AWK : What about the nitrate part? The question does state the presence of nitrate group... So my guess is :

5Cu(NO₃)₂ + 8NH₄OH = 2Cu(OH)₂ + 2[Cu(NH₃)₄](NO3)₂

[rabolisk]

The nitrates are spectator ions.

[AWK]

@AWK : What about the nitrate part? The question does state the presence of nitrate group... So my guess is :

5Cu(NO₃)₂ + 8NH₄OH = 2Cu(OH)₂ + 2[Cu(NH₃)₄](NO3)₂

Ammonia is the limiting reagents in the complexation reaction. You can expect complex ions with 1-4 ammonia molecules. Only when molar ratio of ammonia:Cu²⁺ is 2 or slightly greater you can observe nearly quantitative precipitation of Cu(OH)₂. Of course, at the some stoichiometries some basic salts can be formed, but I do not know if the copper basic nitrates are poorly soluble (I know for example Cu(OH)₂.CuSO₄ is insoluble).
At the excess of ammonia nitrate is a spectator ion.

[Schrödinger]

Guess I didn't know that