If Ksp of Mg(OH)2 is 1.2 × 10-11. Then the highest pH of the 0.1 M solution of Mg2+ ion from which Mg(OH)2 is not precipitated is

Question

If Ksp of Mg(OH)2 is 1.2 × 10-11. Then the highest pH of the 0.1 M solution of Mg2+ ion from which Mg(OH)2 is not precipitated is (A) 4.96 (B) 6.96 (C) 7.54 (D) 9.04

Tardigrade Admin · Accepted Answer

As Ksp of Mg(OH)2 = [Mg2+] [OH-]2 ∴ [OH-]2=(1.2×10-11/0.1)=1.2×10-10 ∴ [OH-]2=1.1×10-5 ∴ [H+]=10-14/1.1×10-5=0.91×10-9 pH=-log[H+]=log 0.91×10-9=9.04

Q. If $K_{s p}$ of $M g (O H)_{2}$ is $1.2 \times 1 0^{- 11}$ . Then the highest pH of the $0.1 M$ solution of $M g^{2 +}$ ion from which $M g (O H)_{2}$ is not precipitated is

$4.96$

$6.96$

$7.54$

$9.04$

Q. If Ksp​ of Mg(OH)2​ is 1.2×10−11. Then the highest pH of the 0.1M solution of Mg2+ ion from which Mg(OH)2​ is not precipitated is

4.96

6.96

7.54

9.04

As Ksp​ of Mg(OH)2​=[Mg2+][OH−]2 ∴[OH−]2=0.11.2×10−11​=1.2×10−10 ∴[OH−]2=1.1×10−5 ∴[H+]=10−14/1.1×10−5=0.91×10−9 pH=−log[H+]=log0.91×10−9=9.04

Q. If $K_{s p}$ of $M g (O H)_{2}$ is $1.2 \times 1 0^{- 11}$ . Then the highest pH of the $0.1 M$ solution of $M g^{2 +}$ ion from which $M g (O H)_{2}$ is not precipitated is

$4.96$

$6.96$

$7.54$

$9.04$