Ammonia forms the complex `[Cu(NH_3)_4]^(2+)` with copper ions in alkaline solution but not in acid solution. The reasons for it is:

Options

A. In alkaline solution `Cu(OH)_(2)` is precipitated which is soluble in excess is alkali
B. Copper hydroxide is amphoteric
C. In acidic solution hydration protects `Cu^(2+)`ions
D. In acidic solution protons coordinates with ammonia molecule formaing `NH_(4)^(+)` ions and `NH_(4)` molecules are not available

Answer

D

Explanation

In acidic solution `NH_(3)` combines with `H^(+)` to give `NH_(4)^(+)` ion.