crude oil and hydrocarbons

Crude oil is found in rocks. Crude oil is a finite resource. —→ if we continue using it at this current rate it will run out one day.

Crude oil is formed over millions of years from the remains of plankton which were buried in mud.

Crude oil is a mixture of molecules called hydrocarbons. E.g methane. CH4.

H

|

H —- C— H

|

H

Hydrocarbons are molecules made up of hydrogen and carbon atoms only.

The molecule ethane which is another hydrocarbon found in crude oil, ethane and methane are called alkanes.

Alkanes general formula: CnH2n+2. —→ if we know the number of carbon atoms in the alkane then we can calculate the number of hydrogen atoms. To do that multiply the number of carbon atoms by 2 and then add 2.

Propane is an alkane with 3 carbon atoms. Draw the structure of propane.

Propane has 3 carbon atoms so n=3. To work out the number of hydrogen atoms we need to multiply the number of carbon atoms by 2 then add 2. 3×2= 6 +2 =8 hydrogen atoms.

Alkanes are saturated molecules.