Which of the following are the example of double salt? (A) FeSO 4 · NH 4 2 SO 4 · 6 H 2 O (B) CuSO 4 · 4 NH 3 · H 2 O (C) K 2 SO 4 · Al 2 SO 4 3 · 24 H 2 O (D) Fe ( CN ) 2 · 4 KCN Choose the correct answer.

Step-by-step solution

A double salt is a salt that contains two or more different cations or anions. (A) FeSO 4 + NH 4 2 SO 4 + 6 H 2 O → FeSO 4 · NH 4 2 SO 4 · 6 H 2 O (Mohr's salt) Mohr’s salt called double salt which contains more than one simple salt. It undergoes complete dissociation in aqueous solutions. (B) CuSO 4 · 4 NH 3 · H 2 O Ammonia solution in water gives a blue precipitate when it combines with a solution of copper salt. The pale blue precipitate of copper hydroxide dissolves in excess of ammonium hydroxide forming tetra