The $pH$ of a solution at $25\,^oC$ containing $0.10\,M$ sodium acetate and $0.03\,M$ acetic acid is ($pK_a$ for $CH_3COOH = 4.57$)

$A$ buffer solution is prepared by mixing equimolar acetic acid and sodium acetate. If $K_{a}$ of acetic acid is $1.78 \times 10^{-5}$,find the $pH$ of the buffer solution.

What is the $OH^-$ ion concentration of a solution containing $0.05 \, M$ ammonium hydroxide and $0.001 \, M$ ammonium chloride? Given $K_b(NH_4OH) = 1.8 \times 10^{-5}$.

Buffer Solution	Volume of $0.1 \ M$ Weak Acid (mL)	Volume of $0.1 \ M$ Sodium Salt (mL)
$I$	$4.0$	$4.0$
$II$	$4.0$	$40.0$
$III$	$40.0$	$4.0$
$IV$	$0.1$	$10.0$

Which of the two sets of buffer solutions have the least $pH$?

Components of a buffer solution are $0.1 \ M \ HCN$ and $0.2 \ M \ NaCN$. What is the $pH$ of the solution? (Given: $pK_a$ of $HCN = 9.30$)

An acidic buffer solution is prepared by mixing a proportionate quantity of