$0.1 \ M$ $CH_3COOH$ is titrated against $0.1 \ M$ $NaOH$. What would be the difference in $pH$ between $1/4$ and $3/4$ stages of neutralization of the acid?

$0.1 \ mol$ of $CH_3NH_2$ $(K_b = 5 \times 10^{-4})$ is mixed with $0.08 \ mol$ of $HCl$ and diluted to $1 \ L$. What will be the $[H^{+}]$ concentration in the solution?

Which of the following acts as a buffer solution?

$A$ 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: $K_b(NH_4OH) = 1.8 \times 10^{-5}$)

$3 \; g$ of acetic acid is added to $250 \; mL$ of $0.1 \; M \; HCl$ and the solution is made up to $500 \; mL$. To $20 \; mL$ of this solution,$\frac{1}{2} \; mL$ of $5 \; M \; NaOH$ is added. The $pH$ of the solution is: [Given: $pK_{a}$ of acetic acid $= 4.75$,molar mass of acetic acid $= 60 \; g/mol$,$\log 3 = 0.4771$]. Neglect any changes in volume.

How to prepare a buffer solution using ammonia $(pK_b = 4.75)$? What is the $pH$ of this buffer if the concentrations of ammonia and ammonium chloride are equal?