An addition reaction is a type of chemical reaction where two or more molecules combine to form a single product.
In these reactions, a double bond or triple bond (usually found in alkenes or alkynes) is broken, and new atoms or groups are added to the carbon atoms.
Example (simple idea):
- In an alkene (like ethene, C₂H₄), the double bond opens up, and hydrogen (H₂) can add across it to form ethane (C₂H₆).
Key points:
- Common in unsaturated compounds (alkenes, alkynes).
- Involves breaking a π bond and forming two new σ bonds.
- Types include:
- Hydrogenation (adding H₂)
- Halogenation (adding X₂ like Cl₂, Br₂)
- Hydration (adding H₂O)
- Hydrohalogenation (adding HX like HCl, HBr)
Overall: An addition reaction reduces multiple bonds (double/triple) into single bonds by adding atoms.