Question

Glucose reacts with conc.HNO$_3$ (Nitric acid) to give

• A. Gluconic Acid
• B. Saccharic Acid
• C. Sorbitol
• D. Fructose

Hint:

To remember the products of glucose oxidation:
- Mild oxidizing agent (e.g., Bromine water): Only the aldehyde group is oxidized $\rightarrow$ Gluconic Acid.
- Strong oxidizing agent (e.g., Conc. Nitric acid): Both the aldehyde and primary alcohol groups are oxidized $\rightarrow$ Saccharic Acid.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the product formed when glucose, an aldohexose, is treated with a strong oxidizing agent like concentrated nitric acid (conc. $HNO_3$).

Step 3: Detailed Explanation:
1. Nature of Reagent: Concentrated nitric acid is a powerful oxidizing agent.
2. Reaction with Glucose: Glucose contains an aldehyde group ($-CHO$) at $C_1$ and a primary alcohol group ($-CH_2OH$) at $C_6$.
3. Oxidation: Conc. $HNO_3$ is strong enough to oxidize both the aldehyde group and the primary alcohol group to carboxylic acid groups ($-COOH$).
4. Product Formation: The resulting dicarboxylic acid is known as Saccharic acid (or glucaric acid). The chemical equation is represented as:
\[ \text{CHO-(CHOH)}_4\text{-CH}_2\text{OH} \xrightarrow{\text{conc. HNO}_3} \text{COOH-(CHOH)}_4\text{-COOH} \]

Step 4: Final Answer:
The oxidation of glucose with concentrated nitric acid yields Saccharic Acid, which corresponds to option (B).