Which of the following nitro compounds will show tautomerism?

Options

A. `C_6H_5NO_2`
B. `(CH_3)_3CNO_2`
C. `CH_3CH_2NO_2`
D. None of the above

Explanation

To determine which nitro compound will show tautomerism, we need to analyze the structure of each compound and check for the presence of alpha hydrogens. Tautomerism typically occurs when there is a hydrogen atom on the carbon adjacent to the functional group (in this case, the nitro group).

### Step-by-Step Solution:

1. **Understanding Tautomerism**:
- Tautomerism is a chemical phenomenon where a compound can exist in two interconvertible forms. For nitro compounds, this usually involves the rearrangement of a hydrogen atom and a shift in double bonds.

2. **Identifying the Compounds**:
- We have three nitro compounds to analyze:
- (A) C6H5NO2 (Nitrobenzene)
- (B) (CH3)3CNO2 (Tert-butyl nitro compound)
- (C) CH3CH2NO2 (Ethyl nitro compound)

3. **Analyzing Compound (A) - Nitrobenzene (C6H5NO2)**:
- Structure: C6H5 (phenyl) connected to NO2.
- There are no alpha hydrogens on the carbon directly attached to the nitro group because the phenyl group is fully substituted.
- **Conclusion**: Does not show tautomerism.

4. **Analyzing Compound (B) - Tert-butyl nitro compound ((CH3)3CNO2)**:
- Structure: A tert-butyl group (three methyl groups attached to a carbon) connected to NO2.
- The central carbon of the tert-butyl group is bonded to three methyl groups and one nitro group, leaving no hydrogen atoms on the alpha carbon.
- **Conclusion**: Does not show tautomerism.

5. **Analyzing Compound (C) - Ethyl nitro compound (CH3CH2NO2)**:
- Structure: Ethyl group (CH3-CH2-) connected to NO2.
- The alpha carbon (the one adjacent to the nitro group) has two hydrogen atoms.
- This allows for tautomerism to occur, where the hydrogen can shift and form a double bond with nitrogen.
- **Conclusion**: Shows tautomerism.

6. **Final Answer**:
- The nitro compound that shows tautomerism is **(C) CH3CH2NO2**.