`(CH_3)_2CH-CH_2CH_3overset(Cl_2//h upsilon)to[N]underset("distillation")overset("Fractional")to[P]`
The number of possible isomers [N] and number of fractions [P] are :

Options

A. (6,6)
B. (6,4)
C. (4,4)
D. (3,3)

Answer

To solve the problem, we need to analyze the chlorination of 2-methylbutane and determine the number of possible isomers formed (N) and the number of fractions obtained through fractional distillation (P).

### Step-by-Step Solution:

1. **Identify the Structure**:
The compound given is 2-methylbutane, which has the following structure:
```
CH3
|
CH3-CH-CH2-CH3
|
CH3
```

2. **Understand Chlorination**:
Chlorination of alkanes involves the substitution of hydrogen atoms with chlorine atoms in the presence of light (UV light). This process can yield different products depending on which hydrogen is replaced.

3. **Identify Possible Substitution Sites**:
In 2-methylbutane, there are two types of hydrogen atoms:
- Primary hydrogens (attached to the terminal carbons)
- Secondary hydrogens (attached to the carbon with the methyl group)

4. **Determine the Products**:
When chlorination occurs, we can replace the following hydrogens:
- **Primary Hydrogens**:
1. 1-chloro-2-methylbutane (from the terminal CH3)
2. 1-chloro-3-methylbutane (from the other terminal CH2)
- **Secondary Hydrogens**:
3. 2-chloro-2-methylbutane (from the carbon with the methyl group)
4. 2-chloro-3-methylbutane (from the adjacent carbon)

5. **Count the Isomers**:
The products formed from the chlorination of 2-methylbutane are:
- 1-chloro-2-methylbutane
- 1-chloro-3-methylbutane
- 2-chloro-2-methylbutane
- 2-chloro-3-methylbutane

Thus, the total number of possible isomers (N) is **4**.

6. **Fractional Distillation**:
Each of these products can be separated through fractional distillation, which is a method used to separate components based on their boiling points. Since we have 4 distinct products, the number of fractions (P) obtained will also be **4**.

### Conclusion:
The number of possible isomers (N) is **4**, and the number of fractions (P) is also **4**.

### Final Answer:
N = 4, P = 4