The $pH$ of blood is maintained due to the mechanism of ...... .

$A$ certain buffer solution contains equal concentrations of $X^-$ and $HX$. If the $K_a$ of $HX$ is $10^{-8}$,then the $pH$ of the buffer solution will be ...... .

The ionization constant $(K_a)$ of a certain weak acid is $10^{-4}$. What should be the $[salt]$ to $[acid]$ ratio if we have to prepare a buffer with $pH = 5$ using this acid and one of its salts?

$20 \, mL$ of $0.2 \, M \, HCN$ is mixed with $10 \, mL$ of $0.2 \, M \, NaOH$. Calculate the $pH$ of the resulting mixture. The $pKa$ value of $HCN$ is $5$.

Which of the following mixtures will form a buffer solution?

Which buffer solution out of the following will have $pH > 7$?