Question

Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because (J1989,1M)

• A. The hydration energy of sodium sulphate is more than its lattice energy
• B. The lattice energy of barium sulphate is more than is hydration energy
• C. The lattice energy has no role to play in solubility
• D. The hydration energy of sodium sulphate is less than its lattice energy

Answer 1

Answer: (A), (B)

The lattice energy of barium sulphate is more than is hydration energy

(a) Correct For greater solubility, hydration energy must be greater than lattice energy.
(b) Correct Greater lattice energy discourage dissolution of a salt.
(c) Incorrect When a salt dissolve, energy is required to break the lattice, which comes from hydration process.
(d) Incorrect Explained in (A).