Chemistry C7- crude oil and hydrocarbons

What is crude oil?

Crude oil is a mixture of compounds (mostly hydrocarbons) formed from dead animals/ plants

What is crude oil made up of?

Ancient biomass/plankton

How long does it take to form crude oil?

Millions of years

How are they formed?

When the ancient biomass falls to the seabed, sand and mud build up ontop. They need high pressure and tempreture to then turn into crude oil

What is crude oil used for?

Transport, generating electricity, making plastics

What are hydrocarbons?

Chains on hydrogen and carbon

What is the formula for Alkane

CnH2n+2

What is the formula for Alkene

CnH2n

CH4

Methane

Butane

C4H10

C2H6

Ethane

Propane

C4H8

Differences between a longer and shorter chain

Shorter

Longer

Low boiling point Higher boiling point

Low viscosity Higher viscosity

Easier to ignite Harder to ignite

Why are longer chains harder to ignite?

Because the intermolecular forces are stronger so oxygen cannot diffuse in between molecules

What is the formula for combustion?

Fuel (hydrocarbon) + oxygen = carbon dioxide + water