What is the concentration of $[H^+]$ in $mol/L$ in a mixed solution of $0.20 \ M \ CH_3COONa$ and $0.10 \ M \ CH_3COOH$? (Given: $K_a$ of $CH_3COOH = 1.8 \times 10^{-5}$)

An acidic buffer is obtained on mixing

The $pK_a$ of an equimolar mixture of sodium acetate and acetic acid is $4.74$. What is the $pH$ of the solution?

$A$ buffer solution contains $0.1 \ mol$ of sodium acetate in $1000 \ cm^{3}$ of $0.1 \ M$ acetic acid. To the above buffer solution,$0.1 \ mol$ of sodium acetate is further added and dissolved. The $pH$ of the resulting buffer is equal to

Which of the following is a buffer solution?

Assertion $(A)$: The $pH$ of a buffer solution containing equal moles of acetic acid and sodium acetate is $4.8$ ($pK_a$ of acetic acid is $4.8$).
Reason $(R)$: The ionic product of water at $25^{\circ} C$ is $10^{-14} \ mol^2 \ L^{-2}$. The correct answer is