[Rattle12]

In our lab experiment, we prepared cadmium sulfate with 0.1 M of thiourea and then adding 6M NH3. I know why we add the thiourea, apparently for the source of sulfide anions, and the ammonia to control the ph. Now, my question is what is the balanced equation for  the reaction with added NH3, and the balance equation when the mixture is  heated? I looked everywhere, and can't seem to find any reaction involving the ammonia..

[Borek]

You "prepared cadmium sulfate with" or you "mixed cadmium sulfate with"?

What is intended product - cadmium sulfide?

What is complete procedure? Have you used just solid cadmium sulfate, or some acidified solution?

ammonia to control the ph

what is the balanced equation for  the reaction with added NH3

Check if you can find complex formation constants for Cd/ammonia. But if ammonia is there just to control pH, it reacts mainly (or only) with water.

[AWK]

Both ammonia and thiourea form complexes with cadmium(II) [sulfate]. Ammonia here is also use as source of hydroxide anions for slow hydrolysis of thiourea to urea loosing sulfide anions in alkaline solution. (Urea after heating can even hydrolyse to ammonia and carbonate). Ammonia itself do not take place directly in reaction of deposition of CdS

[Rattle12]

Yes Borek. I didn't make it clear. We mixed, then heated the solution to a constant 80 C temperature. The product is a yellow precipitate, which is, Cadmium Sulfide, CdS. Any help for the reactions?  thiourea + NH3 + Cadmium acetate --> CdS ?!!

[Borek]

I think AWK gave all the necessary information.