The acidic buffer $(HX + NaX)$ can be best used to maintain the $pH$ in the range $(4 - 6)$. Find the $pK_b$ of $X^-$.

$50 \, mL$ of $0.2 \, M$ ammonia solution is treated with $25 \, mL$ of $0.2 \, M$ $HCl$. If $pK_b$ of ammonia solution is $4.75$,the $pH$ of the mixture will be

If $20 \ mL$ of $0.1 \ M \ NaOH$ is added to $30 \ mL$ of $0.2 \ M \ CH_3COOH$ $(pK_a = 4.74)$,the $pH$ of the resulting solution is

Which of the following may be added to one litre of water to act as a buffer?

The constant acidity and basicity of a buffer solution is due to........

The $pK_a$ of an equimolar mixture of sodium acetate and acetic acid is $4.74$. What is the $pH$ of the solution?