Compound having molecular formula `C_(5)H_(12)O` cannot show

Options

A. Tautomerism
B. Position isomerism
C. Metamerism
D. Functional isomerism

Answer

To determine which phenomenon a compound with the molecular formula C5H12O cannot exhibit, we will analyze the options given. The possible phenomena include tautomerism, position isomerism, metamerism, and functional isomerism.

### Step-by-Step Solution:

1. **Understanding Tautomerism**:
- Tautomerism typically occurs between keto and enol forms. For a compound to show tautomerism, it must contain a carbonyl group (C=O) that can convert to an enol form (C=C with an -OH group).
- Example: Acetone (C3H6O) can exist in keto form (CH3COCH3) and enol form (CH2=C(OH)CH3).

2. **Analyzing C5H12O for Tautomerism**:
- The molecular formula C5H12O suggests that the compound could be an alcohol or ether, but not necessarily a ketone.
- A compound like pentan-3-one (C5H10O) can show tautomerism, but C5H12O does not have a carbonyl group that can convert to an enol form.
- Therefore, C5H12O cannot show tautomerism.

3. **Position Isomerism**:
- Position isomerism occurs when the position of the functional group changes within the same carbon skeleton.
- For example, pentan-1-ol and pentan-2-ol are position isomers of C5H12O.
- Thus, C5H12O can show position isomerism.

4. **Metamerism**:
- Metamerism occurs when compounds have the same molecular formula but different alkyl groups on either side of a functional group.
- For C5H12O, ethers like ethyl propyl ether or butyl methyl ether can exist, satisfying the metamerism condition.
- Therefore, C5H12O can show metamerism.

5. **Functional Isomerism**:
- Functional isomerism occurs when compounds have the same molecular formula but different functional groups.
- For C5H12O, it can exist as an alcohol (like pentan-1-ol) or an ether (like ethyl propyl ether).
- Hence, C5H12O can show functional isomerism.

### Conclusion:
Based on the analysis, the compound with the molecular formula C5H12O cannot show **tautomerism**.

### Final Answer:
The compound having the molecular formula C5H12O cannot show **tautomerism**.

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