Which type of isomerism is shown by pentaone?

Options

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

Explanation

To determine the type of isomerism shown by pentanone, we need to analyze the structure of pentanone and identify the different forms of isomerism it can exhibit.

### Step-by-Step Solution:

1. **Identify the Structure of Pentanone**:
Pentanone is a ketone with the molecular formula C5H10O. The simplest structure of pentanone can be represented as CH3(CH2)3C(=O)CH3, which indicates that there is a carbonyl group (C=O) located within a five-carbon chain.

2. **Determine Chain Isomerism**:
Chain isomerism occurs when there are different arrangements of the carbon skeleton. For pentanone, we can have different structural forms such as:
- 2-Pentanone: CH3C(=O)CH2CH2CH3
- 3-Pentanone: CH3CH2C(=O)CH2CH3
Thus, pentanone exhibits chain isomerism.

3. **Identify Position Isomerism**:
Position isomerism arises when the position of the functional group changes within the same carbon skeleton. In the case of pentanone, the carbonyl group can be located at different positions:
- 2-Pentanone (C=O on the second carbon)
- 3-Pentanone (C=O on the third carbon)
This indicates that pentanone also shows position isomerism.

4. **Examine Functional Isomerism**:
Functional isomerism occurs when compounds have the same molecular formula but different functional groups. For pentanone, we can consider:
- Pentan-2-one (ketone)
- Pentanal (aldehyde)
These compounds have the same molecular formula (C5H10O) but differ in their functional groups (ketone vs. aldehyde), indicating that pentanone also exhibits functional isomerism.

5. **Conclusion**:
Based on the analysis, we can conclude that pentanone exhibits:
- Chain isomerism
- Position isomerism
- Functional isomerism

Therefore, the correct answer is that pentanone shows all types of isomerism mentioned.

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

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