How many methyl hexane are possible :

Answer

To determine how many methylhexane isomers are possible, we need to analyze the structure of hexane and how a methyl group can be substituted onto it.

### Step-by-Step Solution:

1. **Understand the Base Structure**:
- Hexane has the molecular formula C6H14. It consists of a straight chain of six carbon atoms.

2. **Identify Substitution**:
- A methyl group (CH3) can be substituted onto the hexane chain. This means we will replace one hydrogen atom in hexane with a methyl group.

3. **Draw the Straight Chain**:
- The straight-chain structure of hexane is:
```
CH3-CH2-CH2-CH2-CH2-CH3
```

4. **Identify Possible Positions for Methyl Substitution**:
- The methyl group can be attached to different carbon atoms in the hexane chain. The positions are:
- Position 1: CH3-CH2-CH2-CH2-CH(CH3)-CH3 (2-methylhexane)
- Position 2: CH3-CH2-CH(CH3)-CH2-CH2-CH3 (3-methylhexane)
- Position 3: CH3-CH(CH3)-CH2-CH2-CH2-CH3 (4-methylhexane)

5. **Draw the Isomers**:
- **2-Methylhexane**:
```
CH3-CH(CH3)-CH2-CH2-CH2-CH3
```
- **3-Methylhexane**:
```
CH3-CH2-CH(CH3)-CH2-CH2-CH3
```
- **4-Methylhexane**:
```
CH3-CH2-CH2-CH(CH3)-CH2-CH3
```

6. **Count the Isomers**:
- The three distinct structures we have drawn are:
1. 2-Methylhexane
2. 3-Methylhexane
3. 4-Methylhexane

### Conclusion:
- Therefore, there are **three isomers of methylhexane** possible.