Reaction of NaHSO3 with Phenol:
NaHSO3 (sodium bisulfite) reacts with phenol (C6H6O) to form a sodium phenoxide salt (C6H5ONa) and sulfur dioxide (SO2) gas. This reaction is an example of an acid-base reaction, where the NaHSO3 acts as an acid and the phenol acts as a base.

Reaction of NaHSO3 with Carboxylic Acid:
In contrast to its reaction with phenol, NaHSO3 does not react with carboxylic acids. This is because carboxylic acids are much weaker acids compared to phenols. The weak acidity of carboxylic acids is due to the presence of the carboxyl group (-COOH), which exhibits resonance stabilization and electron withdrawing effects.

Explanation in Detail:
1. Acid-Base Reaction with Phenol:
When NaHSO3 reacts with phenol, the acidic hydrogen in NaHSO3 is transferred to the oxygen atom of the phenol. This results in the formation of a sodium phenoxide salt and the release of sulfur dioxide gas.

The reaction can be represented as follows:
NaHSO3 + C6H6O → C6H5ONa + H2O + SO2

The sodium phenoxide salt formed is an ionic compound consisting of a negatively charged phenoxide ion (C6H5O-) and a positively charged sodium ion (Na+). This reaction is similar to the reaction of NaHSO3 with other strong bases, where the acidic hydrogen is transferred to the base to form a salt.

2. Lack of Reaction with Carboxylic Acid:
On the other hand, carboxylic acids are weak acids. The presence of the carboxyl group (-COOH) in carboxylic acids imparts a stabilizing effect due to resonance. This resonance delocalizes the negative charge, making it less reactive towards nucleophiles such as NaHSO3.

The carboxyl group contains a carbonyl group (C=O) and a hydroxyl group (-OH) attached to the same carbon atom. The oxygen atom in the carbonyl group is more electronegative than the hydroxyl group, resulting in electron withdrawal from the hydroxyl group. This electron withdrawal reduces the basicity of the hydroxyl group and makes it less likely to react with an acid like NaHSO3.

Therefore, NaHSO3 does not react with carboxylic acids since the carboxyl group's resonance stabilization makes the hydroxyl group less basic and less prone to protonation by NaHSO3.

In summary, NaHSO3 reacts with phenol to form a sodium phenoxide salt and sulfur dioxide gas due to the stronger acidity of phenols compared to carboxylic acids. The lack of reaction with carboxylic acids can be attributed to the resonance stabilization of the carboxyl group, which reduces the basicity of the hydroxyl group.

Actually NaHSo3 reacts with carboxylic acid but does not react with phenol