c9 - crude oil and fuels

where is crude oil found

in rocks

is crude oil renewable

no

how is crude oil formed

over millions of years from the remains of tiny, ancient sea animals and plants, mainly plankton that were buried in mud

conditions needed to make crude oil

• high pressure
  - high temperature
  - absence of oxygen

how can the mixtures in crude oil be separated

distillation

most of the hydrocarbons in crude oil are what

alkanes

what are alkanes

saturated hydrocarbon

key alkane examples

• methane
  - ethane
  - propane

what general formula do alkanes follow?

C_nH_2n+2

first four alkane molecules

• methane
  - ethane
  - propane
  - butane

properties of short chain hydrocarbons

• lower boiling point
  - higher volatility
  - low viscosity
  - higher flammability

what type of hydrocarbon is most useful

short chain hydrocarbon

why are short chain hydrocarbons most useful

most flammable and produce less smoky flames than large hydrocarbon chains

properties of long chain hydrocarbons

• long chain
  - higher boiling point
  - lower volatility
  - higher viscosity
  - lower flammability

what fractions of crude oil are very useful as fuels

lighter fractions

when hydrocarbons burn in plenty of air what happens

they transfer lots of energy to the surroundings

the products of the complete combustion of a hydrocarbon are {{c1::carbon dioxide}} and {{c2::water}}

incomplete combustion of a hydrocarbon produces what as one of the products

carbon monoxide

in fossil fuels going through incomplete combustion what is the product

carbon monoxide

why is carbon monoxide bad

toxic gas, blood cells carry it instead of oxygen

in order for hydrogen in hydrocarbon fuel to oxidise what has to happen

burn in PLENTY of air

why do we crack hydrocarbons

to make the heavier less in demand fractions more useful

how does cracking hydrocarbons work

in a cracker, the heavy fraction is distilled from crude oil is heated to vaporise the hydrocarbons. the vapour is then either passed over a hot catalyst or mixed with steam and heated to a very high temperature

the chemical process name of cracking hydrocarbons

thermal decomposition

how to tell by name if something is alkane

ends in -ane

how to tell by name if something is alkene by name

if it ends with -ene

alkene meaning

unsaturated hydrocarbon

unsaturated hydrocarbons compounds (alkenes) contain at least one what

double bond between their carbon bonds

alkenes or alkanes: which is more reactive

alkenes

a positive test for an unsaturated hydrocarbon is that it turn {{c1::orange bromine water}} colourless

why can we use orange bromine water to test for alkenes

as alkanes do not react with bromine water

what is cracking

turning large hydrocarbon molecules into smaller ones by passing them over a hot catalyst or mixing them with steam for thermal decomposition

are alkenes or alkanes more reactive

alkenes

how to test for unsaturated hydrocarbon

turns orange bromine water colourless

what is a hydrocarbon

a compound made of hydrogen and carbon only

what forms do hydrocarbons exist in

rings and chains

what is a homologous series

a family of hydrocarbons with similar chemical properties and share a general formula

methane formula

CH4

ethane formula

C2H6

propane

C3H8

butane formula

C4H10

alkanes get less flammable as you increase the number of what

carbons

viscosity icnreases with more

carbons

what is crude oil separated into

bitumen, fuel oil, diesel, kerosene, petrol and gases

what is bitumen used for

surfacing roads and roofes

what is fuel oil used for

ships and power stations

what is diesel used for

lorrie fuel + some cars and trains

what is kerosene used for

airplane fuel

what is petrol used for

fuel for cars

what are gases used for

heating and cooking

what do you need to combust a hydrocarbon fuel

oxygen, heat and fuel