Answer: (d) (ii) and (iv)
Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. The reaction is an example of a double displacement reaction since ammonium and barium are getting displaced from their respective salts. The chemical equation can be represented as
Aluminium sulphate + Barium chloride → Aluminum chloride + Barium sulphate
Al2(SO4)3 + 3BaCl2→ 2AlCl3 + 3BaSO4
The reaction is also known as a precipitation reaction due to the formation of a white precipitate of barium sulphate. Rest other products formed are soluble in water except barium sulphate that precipitates out.