Which of the following classes of organic compounds show metamerism ?

Options

A. ethers
B. Secondary amines
C. ketones
D. All the three

Answer

To determine which classes of organic compounds show metamerism, we first need to understand what metamerism is. Metamerism occurs when two or more compounds have the same molecular formula but differ in the arrangement of alkyl groups around a functional group. This typically happens when there is a functional group present between two alkyl chains.

### Step-by-Step Solution:

1. **Define Metamerism**:
- Metamerism is a type of isomerism where compounds have the same molecular formula but differ in the arrangement of alkyl groups around a functional group.

2. **Identify the Functional Groups**:
- For each class of organic compounds, we need to identify the functional group and see if it allows for different alkyl chains to be attached on either side.

3. **Analyze Ethers**:
- Ethers have the general structure R-O-R.
- Here, R can be different alkyl groups on either side of the oxygen atom.
- Therefore, ethers can show metamerism.

4. **Analyze Secondary Amines**:
- Secondary amines have the general structure R2-NH.
- Similar to ethers, the two R groups can be different alkyl chains.
- Thus, secondary amines can also show metamerism.

5. **Analyze Ketones**:
- Ketones have the general structure R-C(=O)-R'.
- The R and R' groups can be different alkyl chains, allowing for metamerism.
- Therefore, ketones can also show metamerism.

6. **Conclusion**:
- Since ethers, secondary amines, and ketones all allow for different alkyl chains to be attached around their functional groups, they all exhibit metamerism.

### Final Answer:
All of the three classes of organic compounds (ethers, secondary amines, and ketones) show metamerism.

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