crude oil C9

fractional distillation

• crude oil is evaporated

• the gas then rises up the column until it reaches it’s boiling point

• when the boiling points are reached it will condense and is collected

• the top of the column is cool and the bottom is hot

• the short chains have low boiling points and the long chain have high boiling points therefore the short chains collect at the top and the long at the bottom

CH4

methane

C2H6

Ethene

C3H8

propane

C4H10

butane

C5H12

pentane

all alkanes follow this formula

CnH 2n+2

alkanes only contain a

single carbon to carbon bond

incomplete combustion propertys

• insufficent oxygen

• air hole closed

• produces cooler flame

• flame will be yellow

• carbon monoxide formed

• water produced

complete combustion propertys

• sufficent oxygen

• air hole open

• produces hotter flame

• flame will be blue

• carbon dioxide formed

• water produced

complete combustion equation

methane + oxygen → carbon Dioxide + water

incomplete combustion equation

methane + oxygen → carbon monoxide + water

if the fuel burns in oxygen the first product named is… and the test for the product is… and the positive test result is

water

cobalt chloride paper

if water is present from blue to pink

if the fuel burns in oxygen the second product named is… and the test for the product is… and the positive test result is

carbon dioxide

limewater

turns colorless to cloudy

alkenes have

carbon double bonds

alkenes are used for

plastics

we can test for alkenes with

bromine water, in the presence of an alkene the bromine water goes from orange/ yellow to colourless

alkene formula

CnH2n

cracking

• cracking is used because longer chain of hydrocarbons molecules are broken down into smaller ones

• this is done because shorter chains are more in demand but we have more supply of longer chains which are less in demand

• long chains hydrocarbons are heated until they turn into vapour

• a catalyst is added to speed up the reaction

• high temperatures are needed (thermal decomposition)

• The cracked hydrocarbons produce a shorter alkane and an alkene

• During the reaction the catalyst becomes coated in carbon so is pumped into a regenerator- cleaned and used again.