Question

Copper sulphate dissolves in ammonical solution to give deep blue colour. The colour is due to the formation of:

• A. $C{{u}^{2+}}ions$
• B. $Cu{{(OH)}_{2}}$
• C. ${{[Cu{{(N{{H}_{3}})}_{4}}]}^{2+}}$
• D. none of these

Answer 1

Answer: (C)

${{[Cu{{(N{{H}_{3}})}_{4}}]}^{2+}}$

Answer 2

Copper sulphate dissolves in ammonical solution as it forms complex compound with ammonia. $CuS{{O}_{4}}+4N{{H}_{4}}OH\xrightarrow{{}}$ $\underset{\text{deep}\,\text{blue}}{\mathop{[Cu{{(N{{H}_{3}})}_{4}}]\,S{{O}_{4}}}}\,+4{{H}_{2}}O$