Alkenes

In organic chemistry, an alkene is an unsaturated hydrocarbon that contains at least one carbon–carbon double bond. They are also called olefins.  Acyclic alkenes, with only one double bond and no other functional groups, known as mono-enes, form a homologous series of hydrocarbons with the general formula C_nH_2n.

Alkenes have two hydrogen atoms  fewer than the corresponding alkane (with the same number of carbon atoms). The simplest alkene, ethylene (C₂H₄), with the International Union of Pure and Applied Chemistry (IUPAC) name ethene, is the organic compound produced on the largest scale industrially. Aromatic compounds are often drawn as cyclic alkenes, but their structure and properties are different and they are not considered to be alkenes.

General Structure

Example: