GENERAL KNOWLEDGE

Detailed explanation-1: -Iron can displace from CuSO4 solution and hence Cu can be recovered from the solution by adding iron.

Detailed explanation-2: -Answer and Explanation: The correct option is d. Iron is more easily oxidized than copper, therefore it is used in recovering copper from copper sulfate solution.

Detailed explanation-3: -Iron metal is more reactive than copper and displaces it from copper sulphate solution (CuSO4). The deep blue colour of copper sulphate solution fades due to the formation of light green solution of iron sulphate.

Detailed explanation-4: -As more reactive metal can displace less reactive metal from the compound of less reactive metal, so, Iron can displace copper fromcopper sulphate solution but copper cannot displace iron from iron sulphate.

Detailed explanation-5: -Answer: Zinc displaces copper from copper sulphate and generates zinc sulphate solution when added to CuSO4 solution because zinc is a more reactive metal that displaces less reactive metal from its solution. A color change from blue to colorless indicates this.