Sulphates of Be and Mg are readily soluble in water but sulphates of Ca, Sr and Ba are insoluble. This is due to the fact

Options

A. the greater hydration enthapies of `Be^(2+) and Mg^(2+)` overcome the lattice enthalpy
B. high lattice enthalpy of `Be^(2+) and Mg^(2+)` makes them soluble in water
C. solubility decreases from `BeSO_(4)` to `BaSO_(4)` due to increase in ionic size
D. `BeSO_(4) and MgSO_(4)` are ionic in nature while other sulphates are covalent

Answer

A

Explanation

Due to smaller size their lattice enthalpies are high but their greater hydration enthalpies overcome the lattice enthalpies and they become soluble in water. Ca, Sr and Ba sulphates are insoluble in water due ot lower hydration ethalpies.