What is the $pH$ of a solution containing $50 \ mL$ each of $0.1 \ M$ sodium acetate and $0.01 \ M$ acetic acid (in $.5$)? $(pK_{a} \ CH_3COOH = 4.50)$

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

One litre buffer solution was prepared by adding $0.10 \ mol$ each of $NH_3$ and $NH_4Cl$ in deionised water. The change in $pH$ on addition of $0.05 \ mol$ of $HCl$ to the above solution is $............ \times 10^{-2}$ ($Nearest$ $integer$) ($Given$: $pK_b$ of $NH_3 = 4.745$ and $\log_{10} 3 = 0.477$)

The ratio of volumes of $CH_3COOH$ $0.1 \ N$ to $CH_3COONa$ $0.1 \ N$ required to prepare a buffer solution of $pH$ $5.74$ is (Given,$pK_a$ of $CH_3COOH$ is $4.74$)

The $pK_a$ of a weak acid $(HA)$ is $4.5$. The $pOH$ of an aqueous buffered solution of $HA$ in which $50\%$ of the acid is neutralized in its titration with a strong base $(BOH)$ is

$20 \ mL$ of $0.1 \ M \ H_2SO_4$ is added to $30 \ mL$ of $0.2 \ M \ NH_4OH$ solution. The $pH$ of the resultant mixture is [$pK_b$ of $NH_4OH = 4.7$].