The $pH$ of a sodium acetate buffer solution is given by the Henderson-Hasselbalch equation: $pH = pK_a + \log \frac{[Salt]}{[Acid]}$. For acetic acid,if $[Salt] = [Acid] = 0.1 \ M$,then the $pH$ of the solution is: $[K_a = 1.8 \times 10^{-5}]$

$3 \; g$ of acetic acid is added to $250 \; mL$ of $0.1 \; M \; HCl$ and the solution is made up to $500 \; mL$. To $20 \; mL$ of this solution,$\frac{1}{2} \; mL$ of $5 \; M \; NaOH$ is added. The $pH$ of the solution is: [Given: $pK_{a}$ of acetic acid $= 4.75$,molar mass of acetic acid $= 60 \; g/mol$,$\log 3 = 0.4771$]. Neglect any changes in volume.

Which of the following acts as a buffer solution?

$A$ student needs to prepare a buffer solution of propanoic acid and its sodium salt with $pH$ $4$. The ratio of $\frac{[CH_{3}CH_{2}COO^{-}]}{[CH_{3}CH_{2}COOH]}$ required to make the buffer is .....
Given: $K_{a}(CH_{3}CH_{2}COOH) = 1.3 \times 10^{-5}$

The $pH$ of a buffer solution formed by mixing $30 \text{ mL}$ of $0.1 \text{ M } NH_4OH$ and $30 \text{ mL}$ of $1 \text{ M } NH_4Cl$ solutions is $8.6$. The $pK_b$ of $NH_4OH$ is

If the $pH$ of a mixture of $10 \, mL$ of $0.1 \, M \, NH_4OH$ and $10 \, mL$ of $1 \, M \, NH_4Cl$ solution is $8$,the $pK_b$ value of $NH_4OH$ is then closest to