Which will show optical isomerism

Options

A. 3, 3-dichloropentane
B. 2-chloro-2-butanol
C. 2-chloro-2-propanol
D. All of these

Explanation

To determine which compound shows optical isomerism, we need to identify if there is a chiral center present in the molecules. A chiral center is typically a carbon atom that is bonded to four different groups. Here's a step-by-step solution:

### Step 1: Identify the Compounds
We need to analyze the given compounds. The question mentions "three dichloropentane" and "2-propanol."

### Step 2: Analyze 3-Dichloropentane
1. **Structure**: The structure of 3-dichloropentane can be represented as:
- CH3-CHCl-CHCl-CH2-CH3
2. **Chiral Center**: The carbon at position 3 (the one bonded to two chlorine atoms and two different alkyl groups) is a chiral center because it is attached to four different groups:
- Methyl group (CH3)
- Ethyl group (CH2-CH3)
- Chlorine (Cl)
- Hydrogen (H)
3. **Conclusion**: Since it has a chiral center, 3-dichloropentane can show optical isomerism.

### Step 3: Analyze 2-Propanol
1. **Structure**: The structure of 2-propanol can be represented as:
- CH3-CHOH-CH3
2. **Chiral Center**: The carbon atom bonded to the hydroxyl group (OH) is not a chiral center because it is attached to two identical methyl groups (CH3).
3. **Conclusion**: Since there is no chiral center, 2-propanol does not show optical isomerism.

### Final Conclusion
Among the compounds analyzed, **3-dichloropentane** shows optical isomerism because it has a chiral center, while **2-propanol** does not show optical isomerism due to the presence of two identical groups.