Origins of Hydrocarbons

Learning Objectives

  • the origin of crude oil and its use as a source of hydrocarbon raw materials

Summary Notes

What are organic compounds and where do they come from?

  • Organic compounds are the compounds that most biological substances are made out of. They are made up primarily of carbon.

  • Hydrocarbons are a common type of organic compound and they are made up on hydrogen (hydro-) and carbon (-carbon) atoms.

  • The main source of hydrocarbons is crude oil. This is the oil that is extracted from oil fields.

  • Hydrocarbons are come in many different sizes and these have different uses.

  • Crude oil separates these hydrocarbons into their different sizes through fractional distillation.

Fractional Distillation

  • Works by heating crude oil and separating the different hydrocarbons by their boiling points.

  • This works because it relies on dispersion forces and these depend on the size of the molecule.

  • The smaller molecules have a lower boiling point and the larger molecules have higher boiling points.

  • See the simulation below for a demonstration of fractional distillation. Observe how the smaller hydrocarbons rise up and the bigger hydrocarbons settle below.

More Functional Groups

Alcohol

  • Molecules that contain an '-OH' group connected to a C.

  • We call this '-OH' group the hydroxyl group.

  • This '-OH' group allows from hydrogen bonds to form between water molecules, making alcohols more easily dissolvable in water.

Carboxylic Acid

  • Molecules that contain an '-COOH' group.

  • We call this '-COOH' group the carboxyl group.

Amine

  • Molecules that contain an '-NH2' group.

  • We call this '-NH2' group the amine group.

Haloalkane

  • Molecules that contain an '-X' group. X stands for any Halogen (Group 17)

  • X is connected to the central C atom and stands in the place of H.

Video to help build your understanding

Functional Groups

Practice Material

Teacher's Tips:

If we have one C in a formula, we just write it as C, not C1

'n' in the formulas stand for any number from on onwards e.g. if you had a alkane with one carbon, it's formula would be C1H2 x 1+2 which is CH4