For preparing a buffer solution of $pH = 5$ by mixing sodium acetate and acetic acid,the ratio of the concentration of salt and acid should be $(K_a = 10^{-5})$:-

$A$ buffer that is a mixture of acetic acid $(K_a = 2 \times 10^{-5})$ and potassium acetate has $pH = 5.18$. The $\frac{[CH_3COO^{-}]}{[CH_3COOH]}$ ratio in this buffer is approximately:

Which of the following solutions cannot act as a buffer?

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 $pKa$ of a weak acid $HA$ is $4.5$. The $pOH$ of an aqueous buffer solution in which the acid $HA$ is $50\%$ ionized is:

What is the $pH$ of the solution obtained by mixing $5.076 \ g$ of methyl ammonium nitrate $(CH_3NH_3NO_3)$ into $120 \ mL$ of $0.225 \ M$ methylamine $(CH_3NH_2$; $K_b = 4 \times 10^{-4})$?