Which of the following compound will give positive Tollen’s test

Options

A. `CH_(3)`CHO
B.
C. `CH_(3)CH_(2)CH_(2)CH_(2)underset(OH)underset(|)(CH)-OCH_(3)`
D.

Answer

To determine which of the given compounds will give a positive Tollen’s test, we need to understand the nature of the Tollen's reagent and the conditions under which a positive test occurs.

### Step-by-Step Solution:

1. **Understanding Tollen's Test**:
- Tollen's reagent is a solution of silver nitrate (AgNO3) in ammonia (NH3). It acts as a mild oxidizing agent.
- It is specifically used to test for aldehydes. When an aldehyde is present, it gets oxidized to a carboxylic acid, and silver ions (Ag+) in the reagent are reduced to metallic silver (Ag), which forms a silver mirror on the test tube.

2. **Identifying Aldehydes**:
- Only aldehydes can give a positive Tollen’s test. Ketones typically do not react with Tollen's reagent under mild conditions.

3. **Analyzing Each Compound**:
- **Compound 1**: If this compound is an aldehyde (RCHO), it will give a positive Tollen’s test.
- **Compound 2**: If this compound can be converted to an aldehyde under basic conditions (for example, through tautomerization), it will also give a positive test.
- **Compound 3**: Similar to Compound 2, if this compound can form an aldehyde, it will give a positive test.
- **Compound 4**: If this compound does not have the ability to form an aldehyde (for example, if it is a ketone or lacks a reactive hydrogen), it will not give a positive test.

4. **Conclusion**:
- After analyzing all the compounds, we conclude that **Compounds 1, 2, and 3 will give a positive Tollen’s test**, while **Compound 4 will not**.

### Summary:
- **Positive Tollen’s Test**: Compounds 1, 2, and 3 (if they contain aldehyde groups or can be converted to aldehydes).
- **Negative Tollen’s Test**: Compound 4 (if it does not contain an aldehyde group).