The pH of a saturated solution of a metal hydroxide of formula X(OH)2 is 12.0 at 298 K. What is the solubility product of the metal hydroxide at 298 K (in mol3 L-3)?

Question

The pH of a saturated solution of a metal hydroxide of formula X(OH)2 is 12.0 at 298 K. What is the solubility product of the metal hydroxide at 298 K (in mol3 L-3)? (A)  2 × 10-6 (B)  1 × 10-7 (C)  5 × 10- 5 (D)  2 × 10- 5

Tardigrade Admin · Accepted Answer

Given, pH =12 ∴ [ H +]=1 × 10- pH =1 × 10-12 We know that [ H +][ OH -] =Kw=1 × 10-14 ∴ [ OH -] =(1 × 10-14/[ H +]) =(1 × 10-14/1 × 10-12)=1 × 10-2 X( OH )2 dissolves as X ( OH )2 longrightarrow undersetXX 2++ underset1× 10-22OH - ∴ X2+=([ OH -]/2)=(1 × 10-2/2)=5 × 10-3 K sp =[X2+][2 OH -]2 =(5 × 10-3)(1 × 10-2)2 =(5 × 10-3)(1 × 10-4) =5 × 10-7 mol 3 L -3

Q. The $p H$ of a saturated solution of a metal hydroxide of formula $X (O H)_{2}$ is $12.0$ at $298 K$ . What is the solubility product of the metal hydroxide at $298 K$ (in $m o l^{3} L^{- 3}$ )?

$2 \times 1 0^{- 6}$

$1 \times 1 0^{- 7}$

$5 \times 1 0^{- 5}$

$2 \times 1 0^{- 5}$

$5 \times 1 0^{- 7}$

Q. The pH of a saturated solution of a metal hydroxide of formula X(OH)2​ is 12.0 at 298K. What is the solubility product of the metal hydroxide at 298K (in mol3L−3)?

2×10−6

1×10−7

5×10−5

2×10−5