The isomerism shown by butan-1-amine and 2-methylpropan l-amine is

Options

A. chain isomerism
B. position isomerism
C. functional isomerism
D. metamerism

Explanation

To determine the type of isomerism shown by butan-1-amine and 2-methylpropan-1-amine, we can follow these steps:

### Step 1: Identify the Structures
1. **Butan-1-amine** has the structure:
- CH3-CH2-CH2-CH2-NH2
- This means it has a straight-chain structure with 4 carbon atoms and an amine group (-NH2) attached to the first carbon.

2. **2-Methylpropan-1-amine** has the structure:
- CH3-CH(CH3)-CH2-NH2
- This means it has a branched structure with 3 carbon atoms in the main chain and a methyl group (CH3) attached to the second carbon, along with the amine group at the first carbon.

### Step 2: Compare the Structures
- Both compounds have the same molecular formula: C4H11N.
- The difference lies in the arrangement of the carbon skeletons:
- Butan-1-amine has a straight chain (4 carbons).
- 2-Methylpropan-1-amine has a branched chain (3 carbons in the main chain and 1 methyl group).

### Step 3: Determine the Type of Isomerism
- **Chain Isomerism**: This occurs when compounds have the same molecular formula but differ in the arrangement of the carbon skeleton (i.e., straight-chain vs. branched-chain).
- **Position Isomerism**: This occurs when compounds have the same carbon skeleton and functional group but differ in the position of the functional group.
- **Functional Isomerism**: This occurs when compounds have the same molecular formula but different functional groups.
- **Metamerism**: This occurs in compounds with the same functional group but different alkyl chains on either side of the functional group.

### Conclusion
Since butan-1-amine and 2-methylpropan-1-amine have the same molecular formula (C4H11N) but differ in the arrangement of their carbon skeletons (one is straight-chain and the other is branched), they exhibit **chain isomerism**.

### Final Answer
The isomerism shown by butan-1-amine and 2-methylpropan-1-amine is **chain isomerism**.

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