JEE Main levelSingle correct optionDifficulty 2 of 3sb090
The solubility of group 2 sulphates decreases down the group mainly because
Aionisation enthalpy of the metal increases down the group
Bthe sulphate ion hydrates more strongly with larger cations
Cthe lattice enthalpy of the large sulphate salts changes little, while the hydration enthalpy of the cation falls markedly
Dthe lattice enthalpy rises sharply down the group while hydration enthalpy stays constant
Answer: C
For a large anion like sulphate the lattice enthalpy is governed mainly by anion size and falls only slightly from Be to Ba. Hydration enthalpy of the cation falls much more, so ΔHsol becomes less favourable and solubility decreases.