Which one of the following statements is correct ?
 a) Iron sulphate and copper sulphate crystals have same number of water of crystallization
 b) Iron sulphate and zinc sulphate crystals have same number of water of crystallization
 c) Zinc sulphate and copper sulphate crystals have same number of water of crystallization
 d) Iron sulphate, copper sulphate and zinc sulphate crystals each have same number of water of crystallization

Option (b)

Option (b)