Ammonia forms the complex ion [Cu(NH3)4]2+ with copper ions in alkaline solutions but not in acidic solutions. What is the reason for it?

Question

Ammonia forms the complex ion [Cu(NH₃)₄]²⁺ with copper ions in alkaline solutions but not in acidic solutions. What is the reason for it?

In acidic solutions protons coordinate with ammonia molecules forming $NH^+_4$ ions and NH₃ molecules are not available

In alkaline solutions insoluble Cu(OH)₂ is precipitated which is soluble in excess of any alkali

Copper hydroxide is an amphoteric substance

In acidic solutions hydration protects copper ions.

Please login to view the detailed solution steps...