`C_4H_11N` on reaction with `HNO_2` forms tertiary alcohol . Thus , `C_4H_11N` is

Options

A. primary amine
B. secondary amine
C. tertiary amine
D. quaternary ammonium salt

Explanation

To determine the structure of the compound with the molecular formula \( C_4H_{11}N \) that forms a tertiary alcohol upon reaction with \( HNO_2 \), we can follow these steps:

### Step 1: Identify the Type of Amine
The compound \( C_4H_{11}N \) is an amine. Amines can be classified as primary, secondary, or tertiary based on the number of carbon groups attached to the nitrogen atom.

### Step 2: Reaction with \( HNO_2 \)
When amines react with nitrous acid (\( HNO_2 \)), primary amines typically form diazonium salts, which can further react to produce alcohols. Secondary amines do not react in the same way, and tertiary amines do not react with \( HNO_2 \) to form diazonium salts.

### Step 3: Formation of Tertiary Alcohol
Since the question states that the reaction results in a tertiary alcohol, this implies that the original amine must be a primary amine. The primary amine reacts to form a diazonium salt, which then rearranges or reacts to yield a tertiary alcohol.

### Step 4: Determine the Structure of the Amine
Given that the molecular formula is \( C_4H_{11}N \) and it is a primary amine, we can deduce that the structure must allow for the formation of a tertiary alcohol. The simplest structure that fits this description is \( CH_3-CH_2-CH(NH_2)-CH_3 \) or similar variations, where the nitrogen is bonded to one carbon chain and can lead to a tertiary alcohol upon reaction.

### Step 5: Conclusion
Thus, the compound \( C_4H_{11}N \) is a primary amine that can yield a tertiary alcohol upon reaction with \( HNO_2 \).

### Final Answer
The compound \( C_4H_{11}N \) is a primary amine, specifically **butylamine**.

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