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 $5 \times 10^{-10}$.

In which of the following does a buffer solution play an important role?

$A$ buffer solution can be prepared by mixing equal volumes of

In which of the following combinations is buffer action expected?
$(a)$ $NH_4OH + NH_4Cl$
$(b)$ $HCl + NaCl$
$(c)$ $NH_4OH + HCl$ in $2:1$ mole ratio
Select the correct answer using the code given below.

The approximate $pH$ of a solution formed by mixing equal volumes of $0.1 \ M$ sodium propanoate and $0.1 \ M$ propanoic acid (if the dissociation constant of propanoic acid is $1.3 \times 10^{-5}$) will be:

In an acidic buffer,$0.25 \ M$ $CH_3COOH$ is added to $0.125 \ M$ $NaCH_3COO$ solution. Calculate the $pH$ of the buffer. Given $K_a$ of $CH_3COOH = 1.8 \times 10^{-5}$. [Formula: $pH = pK_a + \log \frac{[Salt]}{[Acid]}$]