A buffer solution contains 0.1 mole of sodium acetate dissolved in 1000 cm3 of 0.1 M acetic acid. To the above buffer solution, 0.1 mole of sodium acetate is further added and dissolved. The pH of the resulting buffer is

Question

A buffer solution contains 0.1 mole of sodium acetate dissolved in 1000 cm3 of 0.1 M acetic acid. To the above buffer solution, 0.1 mole of sodium acetate is further added and dissolved. The pH of the resulting buffer is (A) pKa (B) pKa+2 (C) pKa-log 2 (D) pKa+log 2

Tardigrade Admin · Accepted Answer

pH = pK a+ log ([ salt ]/ text [acid] ) When extra 0.1 mole sodium acetate is added [salt] =0.2 mol dm -3 [acid] =0.1 mol dm -3 ∴ PH = p Ka+ log ([0.2]/[0.1]) pH = pK a+ log 2

Q. A buffer solution contains $0.1$ mole of sodium acetate dissolved in $1000 c m^{3}$ of $0.1 M$ acetic acid. To the above buffer solution, $0.1$ mole of sodium acetate is further added and dissolved. The $p H$ of the resulting buffer is

$p K_{a}$

$p K_{a} + 2$

$p K_{a} - l o g 2$

$p K_{a} + l o g 2$

$p H = p K_{a} + lo g \frac{[ s a lt ]}{[acid]}$

When extra $0.1$ mole sodium acetate is added

[salt] $= 0.2 m o l d m^{- 3}$

[acid] $= 0.1 m o l d m^{- 3}$

$∴ P H = p K_{a} + lo g \frac{[ 0.2 ]}{[ 0.1 ]}$

$p H = p K_{a} + lo g 2$

Q. A buffer solution contains 0.1 mole of sodium acetate dissolved in 1000cm3 of 0.1M acetic acid. To the above buffer solution, 0.1 mole of sodium acetate is further added and dissolved. The pH of the resulting buffer is

pKa​

pKa​+2

pKa​−log2

pKa​+log2