How many dichloro products (including stereoisomers) will be formed when `R-2-` chloropentane reacts with `Cl_(2)` in presence is UV radiation?

Answer

To determine how many dichloro products (including stereoisomers) will be formed when R-2-chloropentane reacts with Cl₂ in the presence of UV radiation, we can follow these steps:

### Step 1: Identify the Structure of R-2-Chloropentane
R-2-chloropentane has the following structure:
- The main chain is a pentane (5 carbon atoms).
- There is a chlorine (Cl) atom attached to the second carbon (C-2) of the pentane chain.

The structure can be represented as:
```
CH3
|
CH3-CH-CH2-CH3
|
Cl
```

### Step 2: Understand the Reaction Mechanism
The reaction with Cl₂ in the presence of UV radiation involves a free radical substitution mechanism. This means that the Cl₂ will generate chlorine radicals, which can replace hydrogen atoms in the alkane.

### Step 3: Identify Possible Hydrogen Atoms for Substitution
In R-2-chloropentane, we have:
- 3 hydrogen atoms on C-1
- 1 hydrogen atom on C-2 (which is already substituted with Cl)
- 2 hydrogen atoms on C-3
- 2 hydrogen atoms on C-4
- 3 hydrogen atoms on C-5

### Step 4: Determine the Sites of Chlorination
Chlorination can occur at:
- C-1 (3 possible products)
- C-2 (not applicable since it already has Cl)
- C-3 (2 possible products)
- C-4 (2 possible products)
- C-5 (3 possible products)

### Step 5: Count the Unique Products
1. **Chlorination at C-1**:
- 3 products (due to different configurations)
2. **Chlorination at C-3**:
- 2 products (due to different configurations)
3. **Chlorination at C-4**:
- 2 products (due to different configurations)
4. **Chlorination at C-5**:
- 3 products (due to different configurations)

### Step 6: Total Count of Products
Now, we add the products from each site:
- C-1: 3 products
- C-3: 2 products
- C-4: 2 products
- C-5: 3 products

Total = 3 + 2 + 2 + 3 = 10 products

### Conclusion
Thus, the total number of dichloro products (including stereoisomers) formed when R-2-chloropentane reacts with Cl₂ in the presence of UV radiation is **10**.

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