When $1.0 \ mL$ of dilute $HCl$ acid is added to $100 \ mL$ of a buffer solution with $pH = 4.0$,what will be the resulting $pH$ of the solution?

$A$ buffer solution is prepared by mixing $0.2 \ M$ sodium acetate and $0.1 \ M$ acetic acid. If $pK_{a}$ for acetic acid is $4.7$,find the $pH$.

An acidic buffer solution can be prepared by mixing the solution of

Find the value of $\frac{[NaCN]}{[HCN]}$ given the $pH$ of the buffer solution of $NaCN$ and $HCN$ is $9.3$ and $K_a$ of $HCN$ is $5 \times 10^{-10}$.

$pH$ of a mixture of $1 \ M$ benzoic acid $(pK_a = 4.20)$ and $1 \ M$ $C_6H_5COONa$ is $4.5$. What is the volume of benzoic acid required to prepare a $300 \ mL$ buffer solution (in $mL$)? $[\log 2 = 0.3]$

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 $CH_3COOH = 1.8 \times 10^{-5}$.