Ethylene forms ethylene chlorohydrin by the action of -

Options

A. Dry HCl gas
B. Dry chlorine gas
C. Solution of chlorine gas in water
D. none

Answer

To solve the question of how ethylene forms ethylene chlorohydrin, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- Ethylene (C₂H₄), also known as ethene, is the starting compound.
- We need a reagent that can introduce both chlorine (Cl) and hydroxyl (OH) groups into the ethylene molecule.

2. **Choose the Correct Reagent**:
- The appropriate reagent for forming ethylene chlorohydrin is a solution of chlorine gas (Cl₂) in water, which produces hypochlorous acid (HOCl).

3. **Reaction Mechanism**:
- When ethylene reacts with hypochlorous acid (HOCl), the reaction proceeds as follows:
- The Cl from HOCl acts as the electrophile and adds to one of the carbon atoms of the double bond in ethylene.
- The OH group from HOCl adds to the other carbon atom of the double bond.

4. **Applying Markovnikov's Rule**:
- In this case, since ethylene is symmetrical (both carbon atoms are equivalent), either the Cl or the OH can attach to either carbon without affecting the product.
- The product formed will be 2-chloroethanol, which is also known as ethylene chlorohydrin.

5. **Final Product**:
- The final structure of ethylene chlorohydrin can be represented as:
- CH₂(Cl)-CH₂(OH), where one carbon has a chlorine atom and the other has a hydroxyl group.

### Summary of the Reaction:
- Ethylene + HOCl → Ethylene chlorohydrin (CH₂Cl-CH₂OH)