The solubility product of a salt having general formula MX2, in water is 4 × 10-12, The concentration of M2+ ions in the aqueous solution of the salt is

Question

The solubility product of a salt having general formula MX2, in water is 4 × 10-12, The concentration of M2+ ions in the aqueous solution of the salt is (A) 4.0 × 10-10 M (B) 1.6 × 10-4 M (C) 1.0 × 10-4 M (D) 2.0 × 10-6 M

Tardigrade Admin · Accepted Answer

M X2 leftharpoons undersetsM2++ underset2 s2 X Ks p=[M2+][X-]2 If solubility be s then K sp =(s)(2 s)2=4 s3 4 s3 =4 × 10-12 ∴ s =1 × 10-4 M ∴ M2 =s =1 × 10-4 M

Q. The solubility product of a salt having general formula $M X_{2},$ in water is $4 \times 1 0^{- 12},$ The concentration of $M^{2 +}$ ions in the aqueous solution of the salt is

$4.0 \times 1 0^{- 10} M$

$1.6 \times 1 0^{- 4} M$

$1.0 \times 1 0^{- 4} M$

$2.0 \times 1 0^{- 6} M$

$M X_{2} ⇌ s M^{2 +} + 2 s 2 X$
$K_{s p} = [M^{2 +}] [X^{-}]^{2}$
If solubility be $s$ then
$K_{s p} = (s) (2 s)^{2} = 4 s^{3}$
$4 s^{3} = 4 \times 1 0^{- 12}$
$∴ s = 1 \times 1 0^{- 4} M$
$∴ M^{2} = s = 1 \times 1 0^{- 4} M$

Q. The solubility product of a salt having general formula MX2​, in water is 4×10−12, The concentration of M2+ ions in the aqueous solution of the salt is

4.0×10−10M

1.6×10−4M

1.0×10−4M

2.0×10−6M