Molecular formula `C_3H_9N` represents :

Options

A. `1^@` amine
B. `2^@` amine
C. `3^@` amine
D. Quaternary salt

Answer

To determine what the molecular formula \( C_3H_9N \) represents, we will analyze the formula step by step.

### Step 1: Identify the Elements
The molecular formula \( C_3H_9N \) contains:
- 3 Carbon (C) atoms
- 9 Hydrogen (H) atoms
- 1 Nitrogen (N) atom

### Step 2: Determine the Degree of Unsaturation
The degree of unsaturation can be calculated using the formula:
\[ \text{Degree of Unsaturation} = \frac{(2C + 2 + N - H)}{2} \]
Substituting the values:
\[ \text{Degree of Unsaturation} = \frac{(2 \times 3 + 2 + 1 - 9)}{2} = \frac{(6 + 2 + 1 - 9)}{2} = \frac{0}{2} = 0 \]
A degree of unsaturation of 0 indicates that there are no rings or double bonds in the structure.

### Step 3: Identify Possible Structures
Since there are no double bonds or rings, we can construct the following structures:
1. **Primary Amine**:
- Structure: \( CH_3-CH_2-CH_2-NH_2 \) (Propylamine)

2. **Secondary Amine**:
- Structure: \( CH_3-CH_2-NH-CH_3 \) (N-Methyl Ethylamine)

3. **Tertiary Amine**:
- Structure: \( CH_3-N(CH_3)-CH_2-CH_3 \) (N,N-Dimethylmethamine)

### Step 4: Check for Quaternary Amine
For a quaternary amine, we would need a structure with a nitrogen atom bonded to four carbon atoms. This is not possible with only three carbon atoms available in the molecular formula \( C_3H_9N \).

### Conclusion
The molecular formula \( C_3H_9N \) can represent:
- Primary amine
- Secondary amine
- Tertiary amine

It does not represent a quaternary amine due to the limitation of carbon atoms.

### Final Answer
The molecular formula \( C_3H_9N \) represents primary amine, secondary amine, and tertiary amine.

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