Find the $pH$ when $0.2 \, mol$ of $HCl$ is added to $1 \, L$ of a solution containing $1 \, M$ $CH_3COOH$ and $1 \, M$ $CH_3COO^-$. Assume the total volume remains $1 \, L$. Given $K_a$ for $CH_3COOH = 1.8 \times 10^{-5}$.

To prepare a buffer solution of $pH = 6$ by mixing sodium acetate and acetic acid,what should be the ratio of the concentration of salt to acid? $(K_a = 10^{-5})$

$A$ certain buffer solution contains equal concentrations of $X^{-}$ and $HX$. The $K_a$ for $HX$ is $10^{-8}$. The $pH$ of the buffer is

Equal volumes of $0.5 \ N$ acetic acid and $0.5 \ N$ sodium acetate are mixed. What is the $pH$ of the resultant solution? $(pK_{a}$ of acetic acid $= 4.75)$

What is $[H^{+}]$ of a solution that is $0.01 \ M$ in $HCN$ and $0.02 \ M$ in $NaCN$ ($K_a$ for $HCN = 6.2 \times 10^{-10}$)?

$3 \; g$ 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.