Question

Which of the following is an example of an addition reaction?

• A. Ethene + \(Br_{2}\) \( \rightarrow \) 1,2-dibromoethane
• B. Ethanol \( \rightarrow \) Ethene + \(H_{2}O\)
• C. \(CH_{4}\) + \(Cl_{2}\)\( \rightarrow \) \(CH_{3}Cl\) + HCl
• D. Benzene + \(Br_{2} \)\( \rightarrow \) Bromobenzene

Hint:

Addition reactions typically occur with unsaturated hydrocarbons like alkenes and alkynes, where new atoms or groups are added to the carbon atoms of a double or triple bond.

Answer 1

The Correct Option is A

Step 1: An addition reaction involves two reactants combining to form a single product, typically observed in compounds with double or triple bonds (like alkenes or alkynes). 
Step 2: In Option (1), ethene (an alkene) reacts with bromine \((Br_{2})\) across the double bond, resulting in the formation of 1,2-dibromoethane. This is a classic example of an electrophilic addition reaction. 
Step 3: The other options represent different types of reactions: - Option (2) is a dehydration (elimination) reaction.
- Option (3) is a substitution reaction.
- Option (4) is an example of aromatic electrophilic substitution.
Hence, only Option (1) qualifies as an addition reaction.