Which of the following statement is not correct ?

Options

A. generally Tollen's reagent is used in detection of unsaturation
B. Fehling solution is used in detection of glucose
C. neutral `FeCl_3` is used in detection of phenol
D. `NaHSO_3` is used in detection of carbonyl compound

Answer

To solve the question "Which of the following statement is not correct?", we will analyze each of the provided options one by one.

### Step-by-Step Solution:

1. **Analyze Option 1**:
- The statement claims that "Tollens reagent is used in the detection of unsaturation."
- **Explanation**: Tollens reagent is primarily used to detect aldehydes and some alpha-hydroxy ketones. It does not detect unsaturation (alkenes or alkynes). Therefore, this statement is incorrect.

2. **Analyze Option 2**:
- The statement claims that "Fehling's solution is used for the detection of glucose."
- **Explanation**: Fehling's solution is indeed used to detect reducing sugars, including glucose, which contains an aldehyde group. This statement is correct.

3. **Analyze Option 3**:
- The statement claims that "Neutral FeCl3 is used in the detection of phenol."
- **Explanation**: Neutral FeCl3 (ferric chloride) is used to test for phenolic compounds, producing a violet complex. This statement is also correct.

4. **Analyze Option 4**:
- The statement claims that "NaHSO3 is used in the detection of Carbonyl Compounds."
- **Explanation**: Sodium bisulfite (NaHSO3) reacts with carbonyl compounds (like aldehydes and ketones) to form bisulfite addition products. This statement is correct as well.

### Conclusion:
After analyzing all the options, we find that the only incorrect statement is from **Option 1**: "Tollens reagent is used in the detection of unsaturation."

### Final Answer:
**Option 1** is the statement that is not correct.

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