Ethylene reacts bromine to form-

Options

A. Chloroethane
B. Ethylene dibromide
C. Cyclohexane
D. 1-bromo propane

Answer

To solve the question "Ethylene reacts with bromine to form," we will analyze the reaction step by step.

### Step 1: Identify the Reactants
Ethylene is an alkene with the molecular formula C₂H₄, represented as CH₂=CH₂. Bromine is a diatomic molecule with the formula Br₂.

### Step 2: Understand the Reaction Mechanism
When ethylene reacts with bromine, the double bond (π bond) in ethylene will react with bromine. The π bond is electron-rich and can induce a dipole in the Br₂ molecule, leading to the formation of a bromonium ion intermediate.

### Step 3: Formation of the Bromonium Ion
The double bond in ethylene attacks one of the bromine atoms, forming a cyclic bromonium ion. This intermediate is a three-membered ring where one bromine atom is positively charged and the other is still bonded to the other bromine atom.

### Step 4: Nucleophilic Attack
The other bromine atom (Br⁻) will then attack the more substituted carbon of the bromonium ion. This results in a syn addition of bromine across the double bond of ethylene.

### Step 5: Product Formation
The final product of this reaction is a vicinal dibromide, where two bromine atoms are added to adjacent carbon atoms. The structure can be represented as CH₂Br-CHBr₂.

### Step 6: Naming the Product
The IUPAC name for the product formed is ethylene dibromide, also known as 1,2-dibromoethane.

### Conclusion
Thus, the correct answer to the question "Ethylene reacts with bromine to form" is **ethylene dibromide (1,2-dibromoethane)**.

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