$A$ solution which is resistant to change of $pH$ upon the addition of an acid or a base is known as

$A$ buffer solution has equal volumes of $0.2 \ M \ NH_4OH$ and $0.02 \ M \ NH_4Cl$. The $pK_b$ of the base is $5$. The $pH$ is

The $pH$ of blood in the human body is maintained by $CO_2$ and $H_2CO_3$. What is this process called?

Which of the following is a buffer solution?

Amongst the following solutions,the buffer solution is

$A$ solution is prepared by mixing $10 \ mL$ of $1.0 \ M$ acetic acid and $20 \ mL$ of $0.5 \ M$ sodium acetate and diluted to $100 \ mL$. If the $pK_{a}$ of acetic acid is $4.76$, then the $pH$ of the solution is