Question

Assertion : Na₂SO₄ is soluble in water while BaSO₄ is not.

Reason : Lattice energy of BaSO₄ exceeds its hydration energy.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option (a) Both A and R are correct and R is the correct explanation of A.

Explanation:

(a) Both A and R are correct and R is the correct explanation of A.

Solubility decreases down the group: BeSO₄ > MgSO₄ > CaSO₄ >SrSO₄>BaSO₄ 

As hydration energy decreases due to increase in size of the cation while the lattice energy remains the same.