Addition of aqueous ammonia to a solution of Zn⁺⁺ gives a white precipitate which dissolves in an excess of ammonia because?

joanj

2 years ago

The correct answer is:

C. zinc forms a complex which is readily soluble in excess ammonia

When aqueous ammonia (NH3) is added to a solution containing Zn^2+ ions, a white precipitate of zinc hydroxide (Zn(OH)2) is formed. However, this precipitate dissolves upon the addition of excess ammonia due to the formation of a complex ion.

Zinc ions (Zn^2+) form a complex with ammonia molecules to produce the complex ion [Zn(NH3)4]^2+. This complex ion is soluble in excess ammonia, leading to the dissolution of the white precipitate formed initially