Which one of the following nitroalkanes will give nitrolic acid with `NaNO_2//conc. H_2SO_4`

Options

A. `CH_3-underset(CH_3)underset(|)(CH)-NO_2`
B. `C_2H_5-underset(CH_3)underset(|)overset(CH_3)overset(|)C-NO_2`
C. `CH_3-underset(CH_3)underset(|)(CH)-CH_2-NO_2`
D. All of these

Answer

To solve the question of which nitroalkane will give nitrolic acid with `NaNO2` in the presence of concentrated `H2SO4`, we can follow these steps:

### Step 1: Understand the Reactants
We need to identify the nitroalkanes and understand the role of `NaNO2` and `H2SO4`. Nitroalkanes are organic compounds that contain a nitro group (-NO2) attached to an alkane. `NaNO2` (sodium nitrite) in the presence of concentrated sulfuric acid (`H2SO4`) generates nitrous acid (`HNO2`), which is crucial for the reaction.

**Hint:** Identify the functional groups in the given nitroalkanes and the role of the reagents.

### Step 2: Identify the Structure of Nitrolic Acid
Nitrolic acid is formed when a nitroalkane reacts with nitrous acid. The structure of nitrolic acid typically has the formula R1R2C(NO2)(OH), where R1 and R2 are alkyl groups. The formation of nitrolic acid requires the presence of a hydrogen atom on the carbon adjacent to the nitro group (the alpha carbon).

**Hint:** Look for the presence of an alpha carbon with a hydrogen atom in the nitroalkane structures.

### Step 3: Analyze the Given Nitroalkanes
We need to analyze the provided nitroalkanes to see which one has the required structure. The nitroalkane must have a CH2 group adjacent to the nitro group for the formation of nitrolic acid.

1. **Option A**: Check if it has a CH2 group next to the nitro group.
2. **Option B**: Check for the same.
3. **Option C**: Check for the same.
4. **Option D**: Check for the same.

**Hint:** Focus on the carbon chain and identify the position of the nitro group in relation to the CH2 group.

### Step 4: Determine the Correct Option
After analyzing the structures, the nitroalkane that has a CH2 group adjacent to the nitro group will be able to form nitrolic acid.

- If **Option C** has the structure with a CH2 group next to the nitro group, then it is the correct answer.

**Hint:** The presence of the CH2 group is crucial for the formation of nitrolic acid.

### Step 5: Conclusion
The nitroalkane that will give nitrolic acid with `NaNO2` in the presence of concentrated `H2SO4` is the one with a CH2 group adjacent to the nitro group.

**Final Answer:** The correct option is **C** (if it has the CH2 group adjacent to the nitro group).