What is the pH at which Mg(OH)2 begins to precipitate from a solution containing 0.1 M Mg2+ ions? [Ksp for Mg(OH)2 = 1.0 × 10-11]

Question

What is the pH at which Mg(OH)2 begins to precipitate from a solution containing 0.1 M Mg2+ ions? [Ksp for Mg(OH)2 = 1.0 × 10-11] (A) 4 (B) 6 (C) 9 (D) 7

Tardigrade Admin · Accepted Answer

Ksp for Mg(OH)2 = 1.0 × 10-11 [Mg2+][OH-]2=(0.1)×[OH-]2 =1.0×10-11 [OH-]2=(1×10-11/0.1)=10-10 [OH-]=10-5 ; [H+]=(10-14/10-5)=10-9 pH=9

Q. What is the $p H$ at which $M g (O H)_{2}$ begins to precipitate from a solution containing $0.1 M M g^{2 +}$ ions? $[K_{s p}$ for $M g (O H)_{2} = 1.0 \times 1 0^{- 11}]$

$4$

$6$

$9$

$7$

$K_{s p}$ for $M g (O H)_{2} = 1.0 \times 1 0^{- 11}$
$[M g^{2 +}] [O H^{-}]^{2} = (0.1) \times [O H^{-}]^{2}$
$= 1.0 \times 1 0^{- 11}$
$[O H^{-}]^{2} = \frac{1 \times 1 0 ^{- 11}}{0.1} = 1 0^{- 10}$
$[O H^{-}] = 1 0^{- 5}$ ;
$[H^{+}] = \frac{1 0 ^{- 14}}{1 0 ^{- 5}} = 1 0^{- 9}$
$p H = 9$

Q. What is the pH at which Mg(OH)2​ begins to precipitate from a solution containing 0.1MMg2+ ions? [Ksp​ for Mg(OH)2​=1.0×10−11]

4

6

9

7

Ksp​ for Mg(OH)2​=1.0×10−11 [Mg2+][OH−]2=(0.1)×[OH−]2 =1.0×10−11 [OH−]2=0.11×10−11​=10−10 [OH−]=10−5 ; [H+]=10−510−14​=10−9 pH=9

Q. What is the $p H$ at which $M g (O H)_{2}$ begins to precipitate from a solution containing $0.1 M M g^{2 +}$ ions? $[K_{s p}$ for $M g (O H)_{2} = 1.0 \times 1 0^{- 11}]$

$4$

$6$

$9$

$7$

$K_{s p}$ for $M g (O H)_{2} = 1.0 \times 1 0^{- 11}$
$[M g^{2 +}] [O H^{-}]^{2} = (0.1) \times [O H^{-}]^{2}$
$= 1.0 \times 1 0^{- 11}$
$[O H^{-}]^{2} = \frac{1 \times 1 0 ^{- 11}}{0.1} = 1 0^{- 10}$
$[O H^{-}] = 1 0^{- 5}$ ;
$[H^{+}] = \frac{1 0 ^{- 14}}{1 0 ^{- 5}} = 1 0^{- 9}$
$p H = 9$