Question

When an aqueous solution of copper(II) sulphate is saturated with ammonia, the blue compound crystallises on evaporation. The formula of this blue compound is:

• A. [Cu(NH₃)₄]SO₄·H₂O (square planar)
• B. [Cu(NH₃)₄]SO₄ (tetrahedral)
• C. [Cu(NH₃)₆]SO₄ (octahedral)
• D. [Cu(SO₄)(NH₃)₅] (octahedral)

Hint:

Tetraammine copper(II) sulphate gives intense blue colour.

Answer 1

The Correct Option is A

Step 1: Copper(II) forms a deep blue tetraammine complex.
Step 2: The crystalline compound contains one water molecule.