Which of the following statements are wrong?

Options

A. Ethyl benzene is the chain isomer of xylene.
B. Alkenes can exhibit the position, chain, functional, and geometrical isomerism.
C. Esters and carboxylic acids are examples of metamerism.
D. Metamers belong to different classes of compounds.

Explanation

To determine which statements are wrong regarding isomerism, let's analyze each statement step by step.

### Step 1: Analyze Statement A
**Statement A:** Ethyl benzene is a chain isomer of xylene.

- **Structure of Ethyl Benzene:** Ethyl benzene consists of a benzene ring with an ethyl group (C2H5) attached.
- **Structure of Xylene:** Xylene can refer to three isomers: ortho-xylene, meta-xylene, and para-xylene, each having two methyl groups (CH3) attached to the benzene ring.

**Conclusion for Statement A:** Ethyl benzene and xylene are not chain isomers; they belong to different structural categories. Therefore, this statement is **incorrect**.

### Step 2: Analyze Statement B
**Statement B:** Alkenes can exhibit position, chain, functional, and geometrical isomerism.

- **Position Isomerism:** Alkenes can have different positions for the double bond.
- **Chain Isomerism:** Alkenes can have different carbon skeletons (e.g., straight-chain vs. branched).
- **Functional Isomerism:** Alkenes can be compared with other functional groups, but they primarily exhibit isomerism among alkenes.
- **Geometrical Isomerism:** Alkenes can have cis-trans isomers due to restricted rotation around the double bond.

**Conclusion for Statement B:** This statement is **correct** as alkenes can exhibit all these types of isomerism.

### Step 3: Analyze Statement C
**Statement C:** Esters and carboxylic acids are examples of metamerism.

- **Definition of Metamerism:** Metamerism occurs when compounds with the same functional group have different alkyl chains on either side of the functional group.
- **Esters and Carboxylic Acids:** Esters (RCOOR') and carboxylic acids (RCOOH) are not metamers because they belong to different functional groups.

**Conclusion for Statement C:** This statement is **incorrect** as esters and carboxylic acids do not exhibit metamerism.

### Step 4: Analyze Statement D
**Statement D:** Metamers belong to different classes of compounds.

- **Understanding Metamerism:** Metamers must belong to the same functional group but differ in the arrangement of carbon chains.
- **Conclusion:** Since metamers belong to the same functional group, this statement is **incorrect**.

### Final Conclusion
Based on the analysis:
- **Incorrect Statements:** A, C, and D.
- **Correct Statement:** B.

### Summary of Incorrect Statements:
- Statement A: Ethyl benzene is a chain isomer of xylene. (Incorrect)
- Statement C: Esters and carboxylic acids are examples of metamerism. (Incorrect)
- Statement D: Metamers belong to different classes of compounds. (Incorrect)