Which of the following reagents can be used to differentiate between `ph-underset(O)underset(||)(C)-H` and `CH_(3)CH_(2)OH` ?

Options

A. NaOI
B. Fehling's solution
C. Tollens' reagent
D. `ZnCl_(2)//H`

Explanation

To differentiate between benzaldehyde (C6H5CHO) and ethanol (CH3CH2OH), we can use specific reagents that react differently with aldehydes and alcohols. Here's a step-by-step solution to identify the correct reagents:

### Step 1: Identify the Compounds
- **Benzaldehyde**: An aromatic aldehyde (C6H5CHO).
- **Ethanol**: An aliphatic alcohol (CH3CH2OH).

### Step 2: Analyze the Reagents
We have four reagents to consider:
1. **Sodium Iodide (NaOi)**: This reagent can oxidize alcohols to aldehydes but does not react with aldehydes. It will give a positive test with ethanol.
2. **Fehling's Solution**: This reagent is used to test for aliphatic aldehydes. It will not react with benzaldehyde as it is aromatic.
3. **Tollens' Reagent**: This reagent reacts with both aliphatic and aromatic aldehydes, providing a positive test for benzaldehyde.
4. **Lucas Reagent (Zinc Chloride and HCl)**: This reagent is used to differentiate between primary, secondary, and tertiary alcohols. It will not provide a positive test for ethanol as it is a primary alcohol.

### Step 3: Determine Which Reagents Differentiate the Two
- **NaOi**: Will react with ethanol but not with benzaldehyde.
- **Fehling's Solution**: Will not react with benzaldehyde and does not differentiate between the two.
- **Tollens' Reagent**: Will react positively with benzaldehyde and not with ethanol, thus differentiating the two.
- **Lucas Reagent**: Will not react with ethanol as it is a primary alcohol.

### Conclusion
The reagents that can be used to differentiate between benzaldehyde and ethanol are:
- **Sodium Iodide (NaOi)**: It will react with ethanol.
- **Tollens' Reagent**: It will react with benzaldehyde.

### Final Answer
The correct reagents to differentiate between benzaldehyde and ethanol are **NaOi** and **Tollens' Reagent**.