The buffering action of a mixture of $CH_3COOH$ and $CH_3COONa$ is maximum when the ratio of salt to acid is equal to .......?

$A$ buffer solution is prepared with a concentration of $0.30 \ M \ NH_3$ and $0.20 \ M \ NH_4^+$. If the equilibrium constant for $NH_3$ is $K_b = 1.8 \times 10^{-5}$,what will be the $pH$ of this solution?

Explain the preparation of an acidic buffer solution with an example.

In a mixture of acetic acid and sodium acetate,the ratio of the concentration of the salt to the acid is increased ten times. Then the $pH$ of the solution:

Calculate $[H^{+}]$ of $0.2 \ M$ $HCN$ in $1 \ M$ $KCN$ solution. Given $K_{a(HCN)} = 4 \times 10^{-10}$.

$0.1 \ M$ formic acid solution is titrated against $0.1 \ M \ NaOH$ solution. What would be the difference in $pH$ between $1/5$ and $4/5$ stages of neutralization of acid?