`CH_3-CH_2-underset((X))(CH_2)-C-=N,CH_3-underset((Y))underset(CN)underset(|)(CH)-CH_3`
Relation between (X) and (Y) is

Options

A. Chain isomer
B. Positional isomer
C. Functional isomer
D. Metamers

Answer

To determine the relationship between the compounds \( CH_3-CH_2-(X)-(CH_2)-C \equiv N \) and \( CH_3-(Y)-CN \), we need to analyze their structures and identify their types of isomerism.

### Step-by-Step Solution:

1. **Identify the Molecular Formula:**
- For \( X \): The structure indicates that it has a total of 4 carbon atoms (from \( CH_3-CH_2- \) and \( (CH_2)-C \)), and one nitrile group \( (C \equiv N) \).
- For \( Y \): The structure indicates that it has a total of 4 carbon atoms as well, with one nitrile group \( (CN) \).

2. **Count Atoms:**
- Both compounds have the same number of carbon (C), hydrogen (H), and nitrogen (N) atoms, leading us to conclude that they have the same molecular formula.

3. **Determine the Type of Isomerism:**
- **Chain Isomerism:** This occurs when compounds have the same molecular formula but different arrangements of the carbon skeleton.
- In \( X \), the carbon chain is branched, while in \( Y \), it is straight.
- **Positional Isomerism:** This occurs when the position of a functional group changes within the carbon skeleton.
- In \( X \), the nitrile group \( (C \equiv N) \) is attached to a different carbon than in \( Y \).

4. **Conclusion on Isomerism:**
- Since both compounds have the same molecular formula and differ in the arrangement of the carbon chain and the position of the functional group, they exhibit both chain isomerism and positional isomerism.

5. **Final Relationship:**
- Therefore, the relationship between \( (X) \) and \( (Y) \) is that they are **chain isomers** and **positional isomers** of each other.