Study the following table and select the correct option:

Salt | Acid used | Base used | Nature of Salt

(A) NaCl | HCl | NaOH | Basic

(B) $Na_2CO_3$ | $H_2CO_3$ | NaOH | Neutral

(C) $Na_2SO_4$ | $H_2SO_4$ | NaOH | Acidic

(D) $CH_3COONa$ | $CH_3COOH$ | NaOH | Basic

As stated in Section 2.4.2: 'Salts of a strong acid and a strong base are neutral with pH value of 7. On the other hand, salts of a strong acid and weak base are acidic with pH value less than 7 and those of a strong base and weak acid are basic in nature, with pH value more than 7.'

Applying this rule to each row:

• Row D: $CH_3COONa$ is formed from $CH_3COOH$ (a weak acid) and NaOH (a strong base). Strong base + weak acid $\rightarrow$ basic salt. This matches the table entry 'Basic', so option D is correct.

Why the other options are wrong:

• (A) NaCl is formed from HCl (strong acid) and NaOH (strong base). Strong acid + strong base $\rightarrow$ neutral salt (pH = 7), not basic as stated in the table, so this row is incorrect.
• (B) $Na_2CO_3$ is formed from $H_2CO_3$ (a weak acid) and NaOH (a strong base). Strong base + weak acid $\rightarrow$ basic salt (pH > 7), not neutral as stated in the table, so this row is incorrect.
• (C) $Na_2SO_4$ is formed from $H_2SO_4$ (a strong acid) and NaOH (a strong base). Strong acid + strong base $\rightarrow$ neutral salt (pH = 7), not acidic as stated in the table, so this row is incorrect.