Which of the following statements is/are true of reactions of alkenes and alkynes?
1. As alkenes and alkynes are unsaturated hydrocarbons, their most important reactions are addition reactions.
2. In the reactions involving alkenes and alkynes, π bonds, which are weaker than the C-C σ bonds, are broken, and new σ bonds are formed to the atoms being added.
3. Halogenation of alkenes and alkynes involves addition of halogen atoms.

Question

Quizplus · Accepted Answer

1. As alkenes and alkynes are unsaturated hydrocarbons, their most important reactions are addition reactions. This is true. Alkenes and alkynes are unsaturated hydrocarbons with double and triple bonds respectively. These double and triple bonds can undergo addition reactions where atoms or groups add to the molecule, saturating it with more bonds.
2. In the reactions involving alkenes and alkynes, π bonds, which are weaker than the C-C σ bonds, are broken, and new σ bonds are formed to the atoms being added. This is also true. The π bonds in alkenes and alkynes are weaker than the C-C σ bonds and therefore break during addition reactions. New σ bonds are then formed to the atoms being added, resulting in a saturated molecule.
3. Halogenation of alkenes and alkynes involves addition of halogen atoms. This statement is also true. Halogens, such as chlorine and bromine, can add to alkenes and alkynes via an addition reaction. The double or triple bond is broken and the halogen adds to one of the carbons in the molecule, saturating it with new bonds.

Which of the Following Statements Is/are True of Reactions of Alkenes