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 of alkali
B. Copper hydroxide is amphoteric substance
C. In acidic solution hydration protects `Cu^(2+)` ions
D. In acidic solution protons are coordinated with ammonia molecules forming `NH_(4)^(+)` ions

Answer

D