The principal buffer present in human blood is:

Calculate the $pH$ of a buffer solution containing $0.35 \ M$ weak acid and $0.70 \ M$ of its salt with a strong base if $pK_{a}$ is $4.56$.

An aqueous buffer is prepared by adding $100 \, mL$ of $0.1 \, mol \, L^{-1}$ acetic acid to $50 \, mL$ of $0.2 \, mol \, L^{-1}$ of sodium acetate. If $pK_a$ of acetic acid is $4.76$,the $pH$ of the buffer is

$1 \times 10^{-3} \ \text{mole}$ of $HCl$ is added to a buffer solution made up of $0.01 \ \text{M}$ acetic acid and $0.01 \ \text{M}$ sodium acetate. The final $pH$ of the buffer will be (given, $pK_{a}$ of acetic acid is $4.75$ at $25^{\circ} \text{C}$)

Equal volumes of $0.5 \ N$ acetic acid and $0.5 \ N$ sodium acetate are mixed. What is the $pH$ of the resultant solution? $(pK_{a}$ of acetic acid $= 4.75)$

The $pH$ of blood does not appreciably change by a small addition of acid or a base because blood