Question

Solubility of the alkaline earth metal sulphates in water decreases in the sequence :

• A. Ba > Mg >Sr>Ca
• B. Mg >Ca>Sr> Ba
• C. Ca>Sr> Ba > Mg
• D. Sr>Ca> Mg > Ba

Answer 1

The correct option is B

Mg >Ca>Sr> Ba

Mg $>$ Ca $>$ Sr $>$ Ba

The solubility of sulphate decreases on moving down the group. The values of solubility products which decrease gradually also explain the decrease in solubility on moving down the group.

Metal sulphate $MgS{O}_{4}CaS{O}_{4}SrS{O}_{4}BaS{O}_4$

Solubility product $102.4\times {10}^{-5}7.6\times {10}^{-7}1.5\times {10}^{-9}$