The solubility of Mg(OH)2 (K_sp = 1.6 x 10^-11) in a buffer solution maintained at pH 11 (298 K) is

JEE Advanced levelSingle correct optionDifficulty 3 of 3ie202

The solubility of $Mg (OH) X_{2}$ ( $K_{s p} = 1.6 \times 1 0^{- 11}$ ) in a buffer solution maintained at pH 11 (298 K) is

At pH 11,

[OH X^{-}] = 1 0^{- 3} M

is fixed by the buffer, so

s = [Mg X^{2 +}] = K_{s p} / [OH X^{-}]^{2} = 1.6 \times 1 0^{- 11} /1 0^{- 6} = 1.6 \times 1 0^{- 5} M