In qualitative analysis, H₂S gives a black precipitate in a dilute-HCl-acidified salt solution. The precipitate dissolves in dilute HNO₃ to give a blue solution. What results on adding excess aqueous

Question

In qualitative analysis, H₂S gives a black precipitate in a dilute-HCl-acidified salt solution. The precipitate dissolves in dilute HNO₃ to give a blue solution. What results on adding excess aqueous NH₃?

TestHub · Accepted Answer

The black precipitate is CuS; nitric acid gives Cu²⁺. Excess aqueous NH₃ coordinates Cu²⁺ to form the deep-blue [Cu(NH₃)₄]²⁺ solution.

Chemistry - Complete Pblock- Question with Solution | TestHub

Options:

Doubts & Discussion