The correct relation of pH of salt of weak acid and weak base

Question

The correct relation of pH of salt of weak acid and weak base (A) pH = 7 + (1/2)[pKb +logC] (B) pH = 7 + (1/2)[pKb -logC] (C) pH = - (1/2) [logKa+logKw-logKb] (D) pH = - (1/2) [logKw+logKb-logC]

Tardigrade Admin · Accepted Answer

Correct answer is (c) pH = - (1/2) [logKa+logKw-logKb]

Q. The correct relation of pH of salt of weak acid and weak base

$p H = 7 + \frac{1}{2} [p K_{b} + l o g C]$

$p H = 7 + \frac{1}{2} [p K_{b} - l o g C]$

$p H = - \frac{1}{2} [l o g K_{a} + l o g K_{w} - l o g K_{b}]$

$p H = - \frac{1}{2} [l o g K_{w} + l o g K_{b} - l o g C]$

Correct answer is (c) $p H = - \frac{1}{2} [l o g K_{a} + l o g K_{w} - l o g K_{b}]$

Q. The correct relation of pH of salt of weak acid and weak base

pH=7+21​[pKb​+logC]

pH=7+21​[pKb​−logC]

pH=−21​[logKa​+logKw​−logKb​]

pH=−21​[logKw​+logKb​−logC]

Correct answer is (c) pH=−21​[logKa​+logKw​−logKb​]

$p H = 7 + \frac{1}{2} [p K_{b} + l o g C]$

$p H = 7 + \frac{1}{2} [p K_{b} - l o g C]$

$p H = - \frac{1}{2} [l o g K_{a} + l o g K_{w} - l o g K_{b}]$

$p H = - \frac{1}{2} [l o g K_{w} + l o g K_{b} - l o g C]$

Correct answer is (c) $p H = - \frac{1}{2} [l o g K_{a} + l o g K_{w} - l o g K_{b}]$