The general formula of alkenes is:
CnH2n
Explanation
- C represents the number of carbon atoms.
- H represents the number of hydrogen atoms.
- Alkenes are unsaturated, meaning they have fewer hydrogens than alkanes because of the carbon-carbon double bond.
- This formula applies to acyclic (open-chain) alkenes with one double bond.
Example
- 2 carbons → 4 hydrogens (Ethene)
- 3 carbons → 6 hydrogens (Propene)
- 4 carbons → 8 hydrogens (Butene)
In short:
The general formula CnH2n tells you how many hydrogens are present in an unsaturated hydrocarbon with a double bond, distinguishing alkenes from alkanes.