The numberof all possible products excluding stereoisomers obtained on monochlorination of n-butane and iso-butane are respectively

Options

A. 2 and 3
B. 3 and 2
C. 2 and 1
D. 2 and 2

Answer

To solve the question regarding the number of possible products (excluding stereoisomers) obtained from the monochlorination of n-butane and isobutane, we will follow these steps:

### Step 1: Understand the Structures of n-Butane and Isobutane
- **n-Butane**: The structure is CH3-CH2-CH2-CH3.
- **Isobutane**: The structure is (CH3)2CH-CH3.

### Step 2: Identify the Types of Hydrogens in n-Butane
- In n-butane, we can identify:
- 3 terminal CH3 groups (each has 3 equivalent hydrogens).
- 2 CH2 groups (each has 2 equivalent hydrogens).

Therefore, we have:
- 3 equivalent hydrogens from the terminal CH3.
- 4 equivalent hydrogens from the two CH2 groups (2 from each).

### Step 3: Count the Unique Types of Hydrogens in n-Butane
- The unique types of hydrogens in n-butane are:
- 3 from CH3 (terminal)
- 2 from CH2 (middle)

Thus, there are **2 unique types of hydrogens** in n-butane.

### Step 4: Determine the Number of Monochlorination Products for n-Butane
- Each unique hydrogen can be replaced by a chlorine atom, leading to different products:
- Replacing one of the terminal CH3 hydrogens gives one product.
- Replacing one of the CH2 hydrogens gives another product.

Therefore, the total number of products from n-butane is **2**.

### Step 5: Identify the Types of Hydrogens in Isobutane
- In isobutane, we can identify:
- 3 equivalent hydrogens from the two terminal CH3 groups.
- 1 hydrogen from the central carbon (CH).

### Step 6: Count the Unique Types of Hydrogens in Isobutane
- The unique types of hydrogens in isobutane are:
- 3 from the terminal CH3 groups (equivalent).
- 1 from the central CH.

Thus, there are **2 unique types of hydrogens** in isobutane.

### Step 7: Determine the Number of Monochlorination Products for Isobutane
- Each unique hydrogen can be replaced by a chlorine atom:
- Replacing one of the terminal CH3 hydrogens gives one product.
- Replacing the central CH hydrogen gives another product.

Therefore, the total number of products from isobutane is **2**.

### Final Answer
The number of possible products excluding stereoisomers obtained on monochlorination of n-butane and isobutane are respectively **2 and 2**.