Glucose on reaction with bromine water gives:

Question

Accepted Answer

Glucose on reaction with bromine water gives gluconic acid. Let's explore why Option 3 is the correct answer and why the other options are incorrect.

1. **Explanation for Option 3 (Gluconic acid):**
   - When glucose reacts with bromine water, the aldehyde group (-CHO) present in glucose is oxidized to a carboxylic acid group (-COOH), resulting in the formation of gluconic acid. This reaction is specific to the mild oxidizing nature of bromine water, which selectively oxidizes the aldehyde group without affecting the other hydroxyl groups in glucose. Therefore, gluconic acid is the correct product of this reaction.

2. **Why Option 1 (n-hexane) is incorrect:**
   - n-Hexane is a saturated hydrocarbon with the formula C6H14. It is not related to glucose or its oxidation products. The reaction of glucose with bromine water involves oxidation, not the formation of hydrocarbons. Therefore, n-hexane cannot be a product of this reaction.

3. **Why Option 2 (Saccharic acid) is incorrect:**
   - Saccharic acid, also known as glucaric acid, is formed by the oxidation of both the aldehyde group and the primary alcohol group at the other end of the glucose molecule. This requires a stronger oxidizing agent than bromine water, such as nitric acid. Since bromine water is a mild oxidizing agent, it only oxidizes the aldehyde group to form gluconic acid, not saccharic acid.

4. **Why Option 4 (Bromo glucose) is incorrect:**
   - Bromo glucose would imply the substitution of a bromine atom into the glucose molecule. However, the reaction of glucose with bromine water is an oxidation reaction, not a substitution reaction. Bromine water acts as an oxidizing agent, not as a halogenating agent in this context. Therefore, bromo glucose is not formed in this reaction.

In conclusion, the reaction of glucose with bromine water specifically yields gluconic acid due to the selective oxidation of the aldehyde group, making Option 3 the correct answer.