How many structural isomers are possible from molecular formula `C_(3)H_(9)N`

Options

A. 4
B. 5
C. 2
D. 3

Explanation

To determine how many structural isomers are possible from the molecular formula \( C_3H_9N \), we can follow these steps:

### Step 1: Understanding Structural Isomers
Structural isomers are compounds that have the same molecular formula but different arrangements of atoms. For the formula \( C_3H_9N \), we need to consider different ways to arrange the carbon (C), hydrogen (H), and nitrogen (N) atoms.

### Step 2: Identify Possible Structures
1. **Primary Amine**: The first isomer can be a straight-chain primary amine:
- Structure: \( CH_3-CH_2-CH_2-NH_2 \) (Propylamine)

2. **Secondary Amine**: The second isomer can be a secondary amine:
- Structure: \( CH_3-NH-CH_2-CH_3 \) (N-Methyl-ethanamine)

3. **Tertiary Amine**: The third isomer can be a tertiary amine:
- Structure: \( (CH_3)_2N-CH_2-CH_3 \) (N,N-Dimethylmethanamine)

4. **Another Primary Amine**: The fourth isomer can be another primary amine with a branched structure:
- Structure: \( CH_3-CH(NH_2)-CH_3 \) (Isopropylamine)

### Step 3: Count the Isomers
From the structures identified:
1. Propylamine (Primary)
2. N-Methyl-ethanamine (Secondary)
3. N,N-Dimethylmethanamine (Tertiary)
4. Isopropylamine (Primary)

Thus, we have a total of **4 structural isomers** for the molecular formula \( C_3H_9N \).

### Final Answer
The number of structural isomers possible for the molecular formula \( C_3H_9N \) is **4**.

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