Salt hydrolysis Questions in English

(D) $CH_3COONa$ is a salt of a weak acid $(CH_3COOH)$ and a strong base $(NaOH)$.
For the hydrolysis of a salt of a weak acid and a strong base,the $pH$ is calculated using the formula:
$pH = \frac{1}{2} (pK_w + pK_a + \log C)$
Expanding this,we get:
$pH = \frac{1}{2} pK_w + \frac{1}{2} pK_a + \frac{1}{2} \log C$
Therefore,the correct option is $D$.

(C) Ammonium acetate $(CH_3COONH_4)$ is a salt formed from a weak acid $(CH_3COOH)$ and a weak base $(NH_4OH)$.
For a salt of a weak acid and a weak base,the pH of the solution is given by the formula:
$pH = 7 + \frac{1}{2} pK_a - \frac{1}{2} pK_b$
Since the pH of such a salt solution is independent of the concentration (dilution),the pH remains constant upon dilution.
Given that $pK_a \approx pK_b$,the equation simplifies to:
$pH = 7 + \frac{1}{2} (pK_a - pK_b) = 7 + 0 = 7$
Therefore,the pH of the resulting solution is $7$.