Hydrocarbons

Characteristics

Examples

Aliphatic

Ÿ Less dense than water;

Ÿ Molecule size is inversely proportional to its volatility and water solubility.

Methane, propane, butane (gas at room temperature); hexane, octane, hexadecane (liquidat room temperature); Eicosane, Triacontane and Pentacontane (solid at room temperature).

Cycloaliphatic

Ÿ Contain up to 6 carbon atoms in a ring;

Ÿ Fairly resistant to microbial degradation.

Cyclohexane, methyl cyclohexane, methylcyclopentane, 1,2-dimethylcyclopentane.

Aromatic

Ÿ Very volatile and relatively water-soluble;

Ÿ Havebenzenering;

Ÿ Some are resistant to microbial degradation.

Benzene, naphthalene, toluene, xylene and phenanthrene.