Which of the following statement is correct regarding gluconic acid?

Options

A. Gluconic acid is a dicarboxylic acid
B. Gluconic acid is obtained by oxidation of glucose with `HNO_3`
C. Gluconic acid can form cyclic (acetal/hemiacetal) structure
D. Gluconic acid is a partial oxidation product of glucose

Answer

To determine the correct statement regarding gluconic acid, let's analyze each option step by step.

### Step 1: Understanding Gluconic Acid
Gluconic acid is a carboxylic acid derived from glucose. It is formed when glucose undergoes oxidation.

### Step 2: Analyzing the Statements

1. **Statement A: Gluconic acid is dicarboxylic.**
- **Analysis:** Gluconic acid has only one carboxylic group and one alcohol group. Therefore, this statement is incorrect.

2. **Statement B: It is obtained by oxidation of glucose by SnO3.**
- **Analysis:** Gluconic acid is actually produced by the oxidation of glucose using bromine water (Br2 in water), not SnO3. Thus, this statement is also incorrect.

3. **Statement C: Gluconic acid forms cyclic acetal and hemiacetal.**
- **Analysis:** Acetals and hemiacetals are typically formed from aldehydes and alcohols, and since gluconic acid is a carboxylic acid and not an aldehyde, it does not form acetal or hemiacetal. Hence, this statement is incorrect.

4. **Statement D: Gluconic acid is a partial oxidation product of glucose.**
- **Analysis:** This statement is correct. Gluconic acid is indeed a partial oxidation product of glucose. If glucose were fully oxidized, it would form saccharic acid instead.

### Conclusion
The correct statement regarding gluconic acid is:
- **D: Gluconic acid is a partial oxidation product of glucose.**