Alkynes

Definition

Alkynes are hydrocarbons that contain at least one carbon-carbon triple bond. They have the general formula $C_nH_{2n-2}$.

5 Must Know Facts For Your Next Test

1. Alkynes are unsaturated hydrocarbons, meaning they have fewer hydrogen atoms than alkanes and alkenes of the same carbon count.
2. The simplest alkyne is ethyne, commonly known as acetylene, with the molecular formula $C_2H_2$.
3. Alkynes undergo addition reactions, where reagents add across the triple bond to form more saturated compounds.
4. The presence of a triple bond gives alkynes distinct chemical properties including higher reactivity compared to alkanes and alkenes.
5. In naming alkynes according to IUPAC nomenclature, the suffix '-yne' is used to indicate the presence of a triple bond.

Review Questions

• What is the general formula for alkynes?
• What type of reactions do alkynes typically undergo?
• How does the presence of a triple bond affect the reactivity of alkynes compared to alkanes and alkenes?

Related terms

Alkanes:

Hydrocarbons that contain only single bonds between carbon atoms and have the general formula $C_nH_{2n+2}$. They are also known as saturated hydrocarbons.

Alkenes:

Hydrocarbons that contain at least one carbon-carbon double bond and have the general formula $C_nH_{2n}$. They are also referred to as unsaturated hydrocarbons.

Addition Reaction: A type of chemical reaction where atoms or groups of atoms are added to a molecule without taking any atom away from it. Commonly occurs in unsaturated hydrocarbons like alkenes and alkynes.