Organic Chemistry

a finite resource found in rocks. - mixture of hydrocarbons

molecules that contain hydrogen and carbon atoms only.

Formed over millions of years from the remains of tiny sea creatures called plankton, which were buried in the mud

CnH2n+2

• methane • ethane • propane • butane

• fuels such as petrol, diesel, kerosene, heavy fuel oi solvents lubricants detergents liquified petroleum gas

a family of organic compounds which have the same functional group and similar chemical properties

• have the same general formula • show a gradual variation in physical properties, such as their boiling points • have similar chemical properties

hydrocarbons which have single carbon to carbon bonds, like alkanes

fractional distillation

because different hydrocarbons have different boiling points

• heated crude oil enters a tall fractionating column, which is hot at the bottom and gets cooler towards the top • vapours from the oil rise through the column • vapours condense when they become cool enough • liquids are led out of the column at different heights

• weak intermolecular forces • low boiling points • they don’t condense, but leave the column as gases • flammable • low viscosity

to separate different hydrocarbons

• stronger intermolecular forces • high boiling point • they leave the column as hot liquid bitumen • less flammable

fractions

hydrocarbons with a similar number of carbon atoms

the amount of oxygen available

• carbon dioxide and water are produced • the maximum amount of energy is given out

hydrocarbon + oxygen → carbon dioxide + water

• poor supply of oxygen • water still produced • carbon monoxide and carbon dioxide produced • less energy given out

a reaction in which larger saturated hydrocarbon molecules are broken down into smaller, more useful hydrocarbon molecules,

• the original starting hydrocarbons are alkanes • the products of cracking include alkanes and alkenes, members of a different homologous series

CnH2n