What is the Difference Between Alkanes and Alkenes?

Alkanes and alkenes are both hydrocarbons, meaning they are made up of hydrogen and carbon only. However, they have some key differences:

1. Bonding: Alkanes are saturated hydrocarbons, consisting of single bonds only, while alkenes are unsaturated hydrocarbons, containing at least one carbon-carbon double bond.
2. General Formula: The general formula for alkanes is C(n)H(2n+2), whereas the general formula for alkenes is C(n)H(2n).
3. Geometry and Hybridization: Alkanes have sp3 hybrid orbitals, with carbon atoms bonded to four other atoms (either carbon or hydrogen). Alkenes, on the other hand, have a 120° bond angle at the carbons with the double bond and 109.5° bond angles.
4. Melting and Boiling Points: Alkanes generally have higher melting and boiling points compared to alkenes due to the stronger intermolecular London forces in alkanes.
5. Chemical Properties: Alkanes are relatively stable molecules, but heat or light can activate reactions that involve the breaking of C–H or C–C single bonds, such as combustion. Alkenes, being unsaturated, have the ability to combine with other atoms and participate in various chemical reactions.

Comparative Table: Alkanes vs Alkenes

The main difference between alkanes and alkenes is the presence of a double bond between carbon atoms in alkenes, while alkanes only have single covalent bonds. Both alkanes and alkenes are hydrocarbons, but they have distinct physical and chemical properties. Here is a comparison table of the key differences between alkanes and alkenes:

Examples of alkanes include methane (CH4), ethane (C2H6), and propane (C3H8), while examples of alkenes include ethene (C2H4), propene (C3H6), and butene (C4H8).