Which of the following compounds give positive test with Tollen's reagent ?

Options

A. `H-overset(O)overset(||)(C)-OH`
B.
C. `CH_(3)-underset(OH)underset(|)(CH)-OC_(2)H_(5)`
D. `CH_(3)-overset(O)overset(||)(C)-H`

Explanation

To determine which of the given compounds gives a positive test with Tollen's reagent, we need to understand what Tollen's reagent is and how it works. Tollen's reagent is a solution of silver nitrate in ammonia, and it is used to test for the presence of aldehydes. Aldehydes can reduce the silver ions in Tollen's reagent to metallic silver, resulting in a positive test, which is indicated by a silver mirror forming on the test tube.

### Step-by-Step Solution:

1. **Identify the Functional Groups**: Examine each of the compounds provided in the options (A, B, C, D) and identify their functional groups. The key functional group we are looking for is the aldehyde group (–CHO).

2. **Analyze Each Option**:
- **Option A**: Check if it contains an aldehyde group. If it has a carboxylic acid group (–COOH), it will not give a positive test with Tollen's reagent.
- **Option B**: Look for the presence of an alcohol group (–OH). Alcohols do not react with Tollen's reagent and will not give a positive test.
- **Option C**: Similar to option B, check if it contains alcohol or ether groups. Neither of these will give a positive test with Tollen's reagent.
- **Option D**: Look for the presence of the aldehyde group (C=O with an H attached). If this group is present, it will give a positive test with Tollen's reagent.

3. **Conclusion**: After analyzing all options:
- Option A (Carboxylic acid) - **Negative**
- Option B (Alcohol) - **Negative**
- Option C (Alcohol and Ether) - **Negative**
- Option D (Aldehyde) - **Positive**

Thus, the compound that gives a positive test with Tollen's reagent is **Option D**.