The $pK_b$ of $CN^{\Theta}$ is $4.7$. The $pH$ of a solution prepared by mixing $2.5 \ mol$ of $KCN$ and $2.5 \ mol$ of $HCN$ in water and making the total volume up to $500 \ mL$ is:

Which of the following mixtures will produce a buffer solution with $pH = 9$?

$A$ buffer solution contains $0.1 \ mol$ of sodium acetate dissolved in $1000 \ cm^{3}$ of $0.1 \ M$ acetic acid. To the above buffer solution,$0.1 \ mol$ of sodium acetate is further added and dissolved. The $pH$ of the resulting buffer is

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? $(K_a = 10^{-5})$

At $298 \text{ K}$, a certain buffer solution contains equal concentrations of $X^-$ and $HX$. The $K_b$ for $X^-$ is $10^{-10}$. What is the $pH$ of this buffer solution?

Calculate the $pH$ of a buffer solution containing $0.1 \text{ M } CH_3COOH$ and $0.1 \text{ M } CH_3COONa$ $[K_a = 1.8 \times 10^{-5}]$.