$A$ buffer solution contains $1 \ mol$ of ammonium sulphate and $1 \ mol$ of $NH_4OH$ $(K_b = 10^{-5})$. The $pH$ of the solution will be:

In an acidic buffer,$0.25 \ M$ $CH_3COOH$ is added to $0.125 \ M$ $NaCH_3COO$ solution. Calculate the $pH$ of the buffer. Given $K_a$ of $CH_3COOH = 1.8 \times 10^{-5}$. [Formula: $pH = pK_a + \log \frac{[Salt]}{[Acid]}$]

If $20 \ mL$ of $0.1 \ M \ NaOH$ is added to $30 \ mL$ of $0.2 \ M \ CH_3COOH$ $(pK_a = 4.74)$,find the $pH$ of the resulting solution.

What is the value of $[H^{+}]$ when $0.1 \ mol$ of $CH_3NH_2$ is mixed with $0.08 \ mol$ of $HCl$? Given $K_b = 5 \times 10^{-4}$.

To obtain a buffer which should be suitable for maintaining a $pH$ of about $4 - 5$,we need to have in solution,a mixture of

$A$ buffer solution with $pH = 9$ is prepared by mixing $NH_4Cl$ and $NH_4OH$. Calculate the number of moles of $NH_4Cl$ dissolved in $1.0 \, L$ of $1.0 \, M \, NH_4OH$ solution. (Given: $K_b(NH_4OH) = 1.8 \times 10^{-5}$)