How many moles of sodium acetate should be added to $1 \ L$ of a $0.1 \ M$ solution of $CH_3COOH$ to give a solution of $pH = 5.5$? (Given: $pK_a$ of $CH_3COOH = 4.5$)

In some solutions,the concentration of $H_3O^{+}$ remains constant even when small amounts of strong acid or strong base are added to them. These solutions are known as

$A$ buffer solution is prepared by mixing equimolar acetic acid and sodium acetate. If $K_{a}$ of acetic acid is $1.78 \times 10^{-5}$,find the $pH$ of the buffer solution.

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? $[K_a = 10^{-5}]$

Which of the following combinations will form a basic buffer solution?

Class $XII$ students were asked to prepare one litre of buffer solution of $pH$ $8.26$ by their chemistry teacher. The amount of ammonium chloride to be dissolved by the student in $0.2 \, M$ ammonia solution to make one litre of the buffer is $..... \, g$ (Given $pK_b(NH_3)=4.74$; Molar mass of $NH_3=17 \, g \, mol^{-1}$; Molar mass of $NH_4Cl =53.5 \, g \, mol^{-1}$)