During the titration of $N/10$ acetic acid with $N/10 \, NaOH$,what is the $pH$ of the solution when $25\%$,$50\%$,and $75\%$ of the titration is complete? $[K_a = 10^{-5}]$

$50 \, mL$ of $0.1 \, M \, CH_3COOH$ is being titrated against $0.1 \, M \, NaOH$. When $25 \, mL$ of $NaOH$ has been added,the $pH$ of the solution will be $.... \times 10^{-2}$. (Nearest integer)
(Given : $pK_a(CH_3COOH) = 4.76$)
$\log 2 = 0.30$,$\log 3 = 0.48$,$\log 5 = 0.69$,$\log 7 = 0.84$,$\log 11 = 1.04$

In which of the following does a buffer solution play an important role?

How to prepare a buffer solution using ammonia $(pK_b = 4.75)$? What is the $pH$ of this buffer if the concentrations of ammonia and ammonium chloride are equal?

The $pH$ of a buffer solution decreases by $0.02$ units when $0.12 \ g$ of acetic acid is added to $250 \ mL$ of a buffer solution of acetic acid and potassium acetate at $27^{\circ} C$. The buffer capacity of the solution is

Find the $pH$ of a buffer solution prepared by mixing $300 \, mL$ of $0.3 \, M \, NH_3$ and $500 \, mL$ of $0.5 \, M \, NH_4Cl$. Given $K_b$ for $NH_3 = 1.8 \times 10^{-5}$.