Hydrocarbon

A hydrocarbon is a type of chemical compound. It is made of only hydrogen and carbon atoms.
They can be found in crude oil and are separated by fractional distillation (which means they are separated into different groups). The hydrogen and carbon are bonded with non-polar covalent bonds. Because of its lack of polar covalent bonds, hydrocarbons cannot create hydrogen bonds with water and are hydrophobic.

 Hydrocarbon "families" 
Hydrocarbons are grouped into "families" or "homologous series". There are five main families. The hydrocarbons in each family have a general formula and similar chemical properties, and similar trends in physical properties. This system was approved in 1892 by the International Congress of Chemists, meeting in Geneva.

Alkanes

Alkanes are the simplest hydrocarbons. Their general formula is CnH2n+2.
 Alkane Name Formula Methane CH4 Ethane C2H6 Propane C3H8 Butane C4H10 Pentane C5H12 Hexane C6H14 Heptane C7H16 Octane C8H18 Nonane C9H20 Decane C10H22

Alkenes

Alkenes are similar to alkanes. The main difference between them is that alkenes have a carbon to carbon double bond. The general formula for the alkenes is CnH2n.
 Alkene Name Formula Ethene C2H4 Propene C3H6 Butene C4H8 Pentene C5H10 Hexene C6H12 Heptene C7H14 Octene C8H16 Nonene C9H18 Decene C10H20

Note that there is no "Methene". Methene is not possible as alkenes require a carbon-carbon double bond and methane only has one carbon atom.

Alkynes

Alkynes have a carbon to carbon triple bond. CnH2n-2 is their general formula.
 Alkyne Name Formula Ethyne (Acetylene) C2H2 Propyne C3H4 Butyne C4H6 Pentyne C5H8 Hexyne C6H10 Heptyne C7H12 Octyne C8H14 Nonyne C9H16 Decyne C10H18

"Methyne" does not exist because of methane's one carbon atom.

Cycloalkanes

Cycloalkanes are isomers of alkenes. They have the same general formula (CnH2n), the only difference is that they do not have a carbon to carbon double bond.
 Cycloalkane Name Formula Cyclopropane C3H6 Cyclobutane C4H8 Cyclopentane C5H10 Cyclohexane C6H12 Cycloheptane C7H14 Cycloctane C8H16 Cyclononane C9H18 Cyclodecane C10H20
Note that ethene does not have a cycloalkane as it can only form a straight line.

Alkadiene

Alkadienes have two carbon to carbon double bonds. Their general formula is CnH2n-2. They are isomers of alkynes.

In a similar manner, there can also exist alkatriene (three carbon to carbon bonds) and other forms. The versatile nature of Carbon's chemistry allows for a nearly infinite number of configurations and compounds.

 Aromatic hydrocarbons 

Aromatic hydrocarbons are aromatic organic molecules that form flat ring-shaped bonds. The most simplest of aromatic hydrocarbons are benzene and indole. They can have one ring, heterocyclic, like benzene or 2 rings, bicyclic like napthalene (primary ingredient in mothballs) or many rings, polycyclic like anthracene (red dye colourant).
Their general formula is CnH2n-6, where n is a number greater than or equal to 6.