Dimethyl ketones are usually characterised through

Options

A. Tollens reagent
B. Iodoform test
C. Schiff's test
D. Benedict's reagent

Answer

To determine how dimethyl ketones are characterized, we can analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Dimethyl Ketones**:
- Dimethyl ketones are a type of ketone that contains two methyl groups attached to the carbonyl (C=O) group. The general structure can be represented as CH3C(=O)CH3.

2. **Evaluating the Tests**:
- We have four tests to consider: Tollens reagent, Iodoform test, Schiff's test, and Benedict's reagent.

3. **Tollens Reagent**:
- Tollens reagent is primarily used to oxidize aldehydes to carboxylic acids. It does not react with ketones, including dimethyl ketones. Therefore, this option is incorrect.

4. **Iodoform Test**:
- The Iodoform test is specifically used to detect methyl ketones. Since dimethyl ketones have the structure CH3C(=O)CH3, they contain the methyl ketonic group. When subjected to the Iodoform test, dimethyl ketones will yield a positive result. Thus, this option is correct.

5. **Schiff's Test**:
- Schiff's test is used to detect aldehydes. Since dimethyl ketones are not aldehydes, this test will not be applicable. Therefore, this option is also incorrect.

6. **Benedict's Reagent**:
- Benedict's reagent is used to detect aldehydes and reducing sugars. It does not react with ketones, including dimethyl ketones. Hence, this option is incorrect as well.

7. **Conclusion**:
- Based on the analysis, the test that characterizes dimethyl ketones is the Iodoform test.

### Final Answer:
Dimethyl ketones are usually characterized through the **Iodoform test**.

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