Question

Sodium sulphate is soluble is water whereas barium sulphate is sparingly soluble because:

• A. the hydration energy of sodium sulphate is more than its lattice energy.
• B. the lattice energy of barium sulphate is more than its 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

The correct option is A the hydration energy of sodium sulphate is more than its lattice energy.

The solubility of any salt can be explained by the overall energy release during the hydration process, in case of sodium sulphate the lattice energy is compensated by the hydration energy, so overall the process become exothermic and sodium salt is completely soluble in water.

Hence, option (A) is correct.