Question

What is the coordination entity formed when excess of aqueous kcn is added to an aqueous solution of copper sulphate?

Answer 1

cuso4+kcn=cukc+n2so4

Answer 2

Hey !!

Seems like your question is incomplete

Here is the complete question

What is the coordination entity formed when excess of aqueous KCN is added to an aqueous solution of copper sulphate? Why is it that no precipitate of copper sulphide is obtained when H₂S (g) is passed through this solution ?

Answer :- K₂[Cu(CN)₄] is formed when excess of aqueous KCN is added to an aqueous solution of CuSO₄₄.

       CuSO₄(aq) (Copper sulphate) + 4KCN(aq) (Potassium cyanide) -----> K₂[Cu(CN)₄] (Potassium Tetracyanocuprate) (soluble)+ K₂SO₄ (aq)

As, CN⁻ ions are strong ligands the complex is very stable. It is not replaced by S²⁻ ions when H₂S gas is passed through the solution and thus no precipitate of CuS is obtained.

NOTE :- Kindly remember the chemical reaction ( It is very important ) in the Board exams this chemical reaction carries 2 marks.

Hope it helps you !!