Solubility product constant ( (K\_{sp}) )of salts of types (... | Chemistry | SolveeIt | Solveeit

Today, August 18

Question

Solubility product constant ( $K_{sp}$ )of salts of types $MX_1, MX_ 2 \, and \, M_3 \, X$ 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

$M_3X > MX_2 > MX$

C

$MX_2 > M_2 X > MX_2$

D

$MX > M_3 X > MX_2$

Answer

$MX > M_3 X > MX_2$

Explanation

Solution

MX : $K_{ s p } = S^2 = 4 \times 10^{ - 8 }$
$\Rightarrow S = 2 \times 10^{ - 4 }$
$MX_2 : K_{ s p } = 4 \, S^3 = 3.2 \times 10^{ - 14 } \Rightarrow S = 2 \times 10^{ - 5 }$
$M_3 \, X : K_{ sp } = 27 S^4 = 2.7 \times 10^{ - 15 } \Rightarrow S = 10^{ - 4 }$
Order of solubility is $MX > M_3 X > MX_2$