Which one of the following is an acidic salt?A) N{a_2}C{O_3}B) NaHC{O_3}C) N{H_4}ClD) NaCl

To determine which of the given options is an acidic salt, we need to understand what acidic salts are. An acidic salt is formed from the partial neutralization of a strong acid by a weak base, resulting in a salt that can still donate protons (H⁺ ions) in solution.

Let’s analyze each option:

**A) \( \text{Na}_2\text{CO}_3 \) (Sodium Carbonate)**
- This salt is derived from sodium hydroxide (a strong base) and carbonic acid (a weak acid). It does not act as an acidic salt; it is a basic salt because it tends to hydrolyze and produce hydroxide ions in solution.

**B) \( \text{NaHCO}_3 \) (Sodium Bicarbonate)**
- This salt is formed from sodium hydroxide (a strong base) and carbonic acid (a weak acid). It can donate protons (H⁺) in solution, making it an acidic salt. It is commonly known as baking soda.

**C) \( \text{NH}_4\text{Cl} \) (Ammonium Chloride)**
- This salt is derived from ammonia (a weak base) and hydrochloric acid (a strong acid). It tends to produce H⁺ ions in solution, and it is also considered an acidic salt.

**D) \( \text{NaCl} \) (Sodium Chloride)**
- This salt is formed from sodium hydroxide (a strong base) and hydrochloric acid (a strong acid). It is a neutral salt and does not exhibit acidic properties.

### Conclusion:
Both **B) \( \text{NaHCO}_3 \)** and **C) \( \text{NH}_4\text{Cl} \)** can be considered acidic salts. However, if we strictly follow the definition of an acidic salt as one derived from a strong acid and a weak base, then **C) \( \text{NH}_4\text{Cl} \)** is the more classical example of an acidic salt.

**Final Answer: C) \( \text{NH}_4\text{Cl} \)**