Q48 / 200 · WBJEE 2013 · Chemistry

$1 \times 10^{-3}$ mole of $\mathrm{HCl}$ is added to a buffer solution made up of $0.01 \mathrm{M}$ acetic acid and 0.01 M sodium acetate. The final pH of the buffer will be (given, $\mathrm{p} K_{a}$ of acetic acid is 4.75 at $\left.25^{\circ} \mathrm{C}\right)$

A
4.6
Correct answer
B
4.66
C
4.75
D
4.8

Solution

$\mathrm{CH}_{3} \mathrm{COO}^{-}+\mathrm{H}^{+} \longrightarrow \mathrm{CH}_{3} \mathrm{COOH}$ $$ \begin{aligned} \mathrm{pH}=& \mathrm{pK}_{a}+\log \frac{(\text { salt })}{(\text { acid })}=4.75+\log \frac{0.009}{0.011} \\ &=4.66 \end{aligned} $$

Hence, the correct answer is option: 'B'.

Relevant Questions

A buffer solution contains ml of (M) and ml of (M) . ml of water is added subsequently to the buffer solution. The pH before and after dilut2026Buffer solutions
Which of the following mixtures act(s) as buffer solution?2023Buffer solutions
Aqueous solution of and of identical concentration are provided. The pair (s) of solutions which form a buffer upon mixing is (are)2021Buffer solutions
In which of the following mixed aqueous solutions, at equilibrium? (1) of of (2) of of 0.1 (3) of of (4) of of2016Buffer solutions
The ratio of volumes of (N) to CH COONa 0.1 (N) required to prepare a buffer solution of is (Given, of is2015Buffer solutions
(N) acetic acid is mixed with solution of NaOH. The pH of the resulting solution is of acetic acid is2012Buffer solutions