If a small amount of sodium acetate is added to an equimolar mixture of sodium acetate and acetic acid,the $pH$ of the resulting solution will .......

What is $[H^{+}]$ of a solution that is $0.01 \ M$ in $HCN$ and $0.02 \ M$ in $NaCN$ ($K_a$ for $HCN = 6.2 \times 10^{-10}$)?

Which of the following mixtures is called an acidic buffer?

Assertion : In a titration of weak acid and $NaOH$,the $pH$ at half equivalence point is $pK_a$.
Reason : At half equivalence point,it forms an acidic buffer and the buffer capacity is maximum where $[acid] = [salt]$.

$0.1 \ mol$ of $CH_3NH_2$ $(K_b = 5 \times 10^{-4})$ is mixed with $0.08 \ mol$ of $HCl$ and diluted to $1 \ L$. The $[H^{+}]$ in the solution is:

How to prepare a buffer solution using ammonia $(pK_b = 4.75)$? What is the $pH$ of this buffer if the concentrations of ammonia and ammonium chloride are equal?