C9

a finite resource found in rocks dark, smelly liquid mixture of hydrocarbons

over millions of years when plankton (remains of ancient animals and plants) were covered in mud and then layers of rock were laid on top creating conditions of high pressure and temp and no oxygen to make crude oil

the process that separates liquids with different boiling points

the substances with different boiling points that crude oil is separated into

all the carbon - carbon bonds are single covalent bonds so they contain as many hydrogen atoms as possible in each molecule

Cn H(2n+2)

low boiling point high volatility (tendancy to turn to gas) low viscosity (runny) high flammability (burns easily)

make good fuels as they ignite and burn easily with less smoky flames

crude oil is vaporised and fed in near the bottom of the fractioning column the column is hot at the bottom and cool at the top (temp decreases going up column) gases move up the column and hydrocarbons condense when they reach the temp of their boiling points

the ones with the smallest molecules and the lowest boiling points (piped out as gases)

long chains with high boiling points that cool to form very thick liquids or solids

carbon dioxide and water

some heavier fractions are not in high demand. They are thick with high boiling points so hard to vaporise and don’t burn easily- not good fuels they can be broken down into smaller, more useful hydrocarbons

at an oil refinery in steel vessels called crackers. The heavy fraction is heated to vaporise and the vapour is either: 1) passed over a hot catalyst 2) mixed with steam and heated

thermal decomposition

an unsaturated hydrocarbon (contains at least one double bond)

an unsaturated hydrocarbon (alkene) turns the orange bromine water colourless but the saturated hydrocarbon (alkane) doesn’t react with it so it stays orange