Which of the following types of isomerism is shown by pentanone

Options

A. Chain isomerism
B. Position isomerism
C. Fuctional isomerism
D. All of these

Explanation

To determine the type of isomerism shown by pentanone, we need to analyze its structure and the possible variations that can occur. Pentanone is a ketone with the molecular formula C5H10O. Let's break down the types of isomerism it can exhibit:

### Step-by-Step Solution:

1. **Identify the Structure of Pentanone**:
- Pentanone has the general formula CnH2nO for ketones. For n = 5, the formula is C5H10O.
- The simplest structure of pentanone is 2-pentanone, where the carbonyl group (C=O) is located at the second carbon.

2. **Types of Isomerism**:
- Isomerism can be classified into two main categories: structural (or constitutional) isomerism and stereoisomerism.
- Structural isomerism can further be divided into chain isomerism, position isomerism, and functional isomerism.

3. **Chain Isomerism**:
- Chain isomerism occurs when the carbon skeleton differs. For pentanone, we can have different arrangements of the carbon chain, such as 3-pentanone or 4-pentanone.
- Example: 2-pentanone and 3-pentanone are chain isomers.

4. **Position Isomerism**:
- Position isomerism occurs when the position of the functional group changes. In pentanone, the position of the carbonyl group can be at different carbon atoms.
- Example: 2-pentanone and 3-pentanone are position isomers.

5. **Functional Isomerism**:
- Functional isomerism occurs when compounds have the same molecular formula but different functional groups. However, since pentanone is a ketone, it does not exhibit functional isomerism with other ketones or aldehydes.

6. **Conclusion**:
- Pentanone exhibits both chain isomerism and position isomerism. Therefore, the types of isomerism shown by pentanone are chain isomerism and position isomerism.

### Final Answer:
Pentanone shows chain isomerism and position isomerism.