Question

Given that Potassium Nitrate and copper(II) sulfate dissolve in water to form a colourless solution and blue solution respectively, which of the following substances cannot be obtained by crystallisation from a solution?
(A)Sugar
(B)Chalk
(C)Copper (II) Sulfate
(D)Potassium Nitrate

Answer 1

Answer:(B) chalk

Explanation:

Water of crystallisation is the fixed number of water molecules present in one formula unit of a salt. Five water molecules are present in one formula unit of copper sulphate. Chemical formula for hydrated copper sulphate is Cu SO 4 . 5H 2 O

According to qus (D) can be formed

Chalk contain calcium that’s not in qus so (b) can be answer