Find the concentration of sodium acetate when added to $0.1 \ M$ solution of acetic acid to form a buffer solution of $pH = 5.5$ (in $M$)? $(pK_{a} \text{ of } CH_{3}COOH = 4.5)$

$A$ buffer solution contains equal concentrations of weak acid and its salt with a strong base. Calculate the $pH$ of the buffer solution if the dissociation constant of the weak acid is $1.8 \times 10^{-5}$.

Which of the following mixtures forms an acidic buffer?

Calculate the $pH$ of a buffer solution containing $0.01 \ M$ salt and $0.004 \ M$ weak acid. $(pK_{a} = 4.762)$

Which mixture forms a buffer when dissolved in $1 \, L$ of water?

Find $pH$ of the resultant solution formed by the addition of $500 \ mL$ $0.1 \ M$ $Ba(OH)_2$ and $500 \ mL$ $0.6 \ M$ $NH_4Cl$ in $1 \ L$ pure $H_2O$ at $25 \ ^oC$ (Use $\log \ 2 = 0.3$,$\log \ 3 = 0.5$,$\log \ 5 = 0.7$,$K_b(NH_3) = 10^{-5}$)