A solution contains 0.010 M Mg^2+ (K_sp of Mg(OH)2 = 1.6 x 10^-11; take log 2 = 0.301) at 298 K. Choose the correct statement(s).

Mg(OH)2 starts to precipitate at pH approx 9.60

No precipitate forms if the pH is held at 9.00

A precipitate forms if the pH is raised to 10.00

Mg(OH)2 starts to precipitate at pH approx 9.60

No precipitate forms if the pH is held at 9.00

A precipitate forms if the pH is raised to 10.00

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3ie215

A solution contains $0.010 M$ $Mg X^{2 +}$ ( $K_{s p}$ of $Mg (OH) X_{2} = 1.6 \times 1 0^{- 11}$ ; take $lo g 2 = 0.301$ ) at 298 K. Choose the correct statement(s).

Precipitation starts when

[OH X^{-}]^{2} \times 0.010 = K_{s p}

, i.e.

[OH X^{-}] = 4 \times 1 0^{- 5} M

(pH

= 9.60

). Ionic products: pH 9.00 gives

1.0 \times 1 0^{- 12}

(below

K_{s p}

); pH 10.00 gives

1.0 \times 1 0^{- 10}

(above); pH 9.30 gives

4.0 \times 1 0^{- 12}

(below

1.6 \times 1 0^{- 11}