Addition reaction

Definition

An addition reaction is a chemical reaction where atoms or groups are added to a double or triple bond in an organic molecule, resulting in the saturation of the bond. These reactions are typical in alkenes and alkynes.

5 Must Know Facts For Your Next Test

1. Addition reactions involve the breaking of $\pi$ (pi) bonds and formation of new $\sigma$ (sigma) bonds.
2. They are classified into electrophilic, nucleophilic, and free-radical addition reactions based on the nature of the attacking species.
3. Hydrogenation is an example where hydrogen is added to a carbon-carbon double bond.
4. Markovnikov's rule often applies in addition reactions, predicting that hydrogen will add to the carbon with more hydrogen atoms already attached.
5. Catalysts like palladium or platinum can be used to facilitate certain addition reactions like hydrogenation.

Review Questions

• What type of bonds are broken and formed during an addition reaction?
• Give an example of an addition reaction and explain its significance.
• How does Markovnikov's rule apply to addition reactions?

Related terms

Electrophilic Addition: A type of addition reaction where an electron-rich double or triple bond reacts with an electron-deficient species.

Hydrogenation:

An addition reaction where hydrogen atoms are added to a carbon-carbon multiple bond in the presence of a catalyst.

Markovnikov's Rule: A rule stating that during the addition of HX to an alkene, the hydrogen atom attaches itself to the carbon with more hydrogen substituents.