What is the action of nitrous acid on :
(a) Primary nitroalkane
(b) Secondary nitroalkane
(c) Tertiary nitroalkane

Explanation

To understand the action of nitrous acid on primary, secondary, and tertiary nitroalkanes, we can break down the reactions step by step.

### Step 1: Action of Nitrous Acid on Primary Nitroalkane
1. **Definition**: A primary nitroalkane is one where the nitro group (-NO2) is attached to a terminal carbon atom.
2. **Reaction**: When a primary nitroalkane (R-CH2-NO2) reacts with nitrous acid (HNO2), it forms a nitroso compound.
- The reaction can be represented as:
\[
R-CH_2-NO_2 + HNO_2 \rightarrow R-CH_2-N=O + H_2O
...