Q. Solubility product constant [$K_{sp}$] of salts of types $MX,\ MX_{2}\ and\ M_{3}X$ at temperature $‘T’$ are $4.0 \times 10^{- 8},3.2 \times 10^{- 14}\ and\ 2.7 \times 10^{- 15}$respectively. Solubilities ($mol,\ dm^{- 3}$) of the salts at temperature $‘T’$ are in the order
A) $MX > MX_{2} > M_{3}X$
B) $M_{3}X > MX_{2} > MX$
C) $MX_{2} > M_{3}X > MX$
D) $MX > M_{3}X > MX_{2}$
Explanation
(d)
[table] Salt | Solubility product | Solubility ; $MX$ | $S_{1}^{2} = 4.0 \times 10^{- 8}\$ | $S_{1} = 2 \times 10^{- 4}$ ; $MX_{2}$ | $4S_{2}^{3} = 3.2 \times 10^{- 14}$ | $S_{2} = 2 \times 10^{- 5}$ ; $M_{3}X$ | $27S_{3}^{4} = 2.7 \times 10^{- 15}$ | $S_{3} = 1 \times 10^{- 4}$ [/table]
Thus, solubility order=$\ MX > M_{3}X > MX_{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.