The pH of a saturated aqueous solution of a hydroxide M(OH)2 at 298 K is 10.60. Given 10^-3.4 = 3.98 x 10^-4, calculate K_sp in units of 10^-11 (two decimals; use the given value of [OH^-]).

JEE Advanced levelNumerical answerDifficulty 3 of 3ie208

The pH of a saturated aqueous solution of a hydroxide $M (OH) X_{2}$ at 298 K is 10.60. Given $1 0^{- 3.4} = 3.98 \times 1 0^{- 4}$ , calculate $K_{s p}$ in units of $1 0^{- 11}$ (two decimals; use the given value of $[OH X^{-}]$ ).

Numerical answer type, answer in x 10^-11, tolerance 0.03.

pOH

= 3.40

, so

[OH X^{-}] = 3.98 \times 1 0^{- 4} M

and

[M X^{2 +}] = \frac{1}{2} [OH X^{-}] = 1.99 \times 1 0^{- 4} M

K_{s p} = [M X^{2 +}] [OH X^{-}]^{2} = 3.2 \times 1 0^{- 11}