Asked by Cheezel

Aqueous sodium hydroxide is added to a mixture of an aqueous solution of X with some aluminium alloy. On warming, ammonia gas is evolved. When X is treated with aqueous ammonia, a white precipitate that is soluble in excess aqueous ammonia is obtained. What could be the identity of X?
A Ammonium nitrate
B Aluminium sulfate
C Zinc hydroxide
D Zinc nitrate

Could someone explain how to get the answer, thks!