C9 Flashcards
What atoms do hydrocarbons contain?
Hydrogen and carbon atoms
What is the simplest hydrocarbon you can get?
Alkanes
What’s the alkanes formula?
CnH2n+2
What are alkenes apart of?
Homologous
What are alkenes?
Saturated compounds ( 4 single covalent bonds )
What are the first four alkanes
Methane,ethane,propane and butane
Formula for methane?
CH4
Formula for ethane?
C2H6
Formula for propane?
C3H8
Formula for butane?
C4H10
What happens as the chain gets longer?
Hydrocarbon properties change
The shorter the carbon chain…
More runny a hydrocarbon is
What is a charecteristic of a shorter carbon chain?
They are more volatile (lower boiling point)
More flammable the hydrocarbon is
What are short chain hydrocarbons used as?
Bottled gases
When does complete combistion occur?
When there’s plenty of oxygen
What is the waste product in complete combustion?
Carbon dioxide and water vapour
Hydrogen + oxygen =
Carbon dioxide + water + (energy)
During combustion what is oxidised?
Carbon and hydrogen
?
.
What is 1 example crude oil is used to make?
Fuels
How often is crude oil made?
Over a long period of time
What type of fuel is a crude oil
A fossil fuel
How is crude oil made?
From the remains of plants and animals that died million of years ago (plankton)
Where can crude oil be found?
The remains from years ago which can drilled up from the rocks
Whats the issue with fossil fuels?
They are non renewable fuels and they are being used up faster than being made. And one day they’ll run out
Name some fossil fuels?
Coal, oil and gas
What can fractional distilation be used to?
Seperate hydrocarbons
What are crude oils?
A mixture of lots of different hydrocarbons (most alkenes)
How are compounds in crude oils seperated?
1) The oil is heated and most of it turns to gas and the gases enter a fractionating column
2) In the column theres a temperature gradient
3) The longer hydrocarbons have higher boiling points. They condense the liquid and drain early on. The shorter hydrocarbons have lower boiling points and condense and drain at the top of the column.
4) You finally end up with crude oil seperated in different fractions
What does LPG mostly contain?
Propane and butane
APR 3C
Cool
APR 8C
Petrol
APR 15C
Kerosene
APR 20C
Disel oil
Apr 40C
Heavy fuel oil or lubricating oil
What element is Very hot
Bitumen
What’s temperature gradient?
It’s hot at the bottom and cooler as you go up
What is made from crude oil?
Diesel oil, kersesone, heavy fuel oil and LPG
What does the petrochemical industry use the hydrocarbons from crude oil for?
- feedstock to make new compounds for the use of polymers,solvents,lubricants and detergents
What are all the products you get from crude oil an example of?
Organic compounds
Why do you get a variety of products?
Carbon atoms can bond together to form the homologous series
What does cracking mean?
Splitting up long chain hydrocarbons
Why are short chain hydrocarbons good?
They’re flammable and make good fuels that are in high demand
Why are long chain hydrocarbons unuseful?
They fom thick gloopy liquids
How are the longer carbon atoms more useful?
By using cracking
What does cracking also produce?
Alkenes
What are alkenes?
They are used as a starting material to make other compounds and can be used to make polymers
What type of reaction is cracking?
Thermal decomposition
What is thermal decomposition?
Breaking molecules down by heating them
What are the steps of thermal decomposition?
1) Heat the long chain hydrocarbons and turn them into gas(vapour)
2) the vapour is passed to a hot powered alaminium oxide catalyst
Whats catalystic cracking?
The long chain molecules split apart on the surface of the catalyst
Whats steam cracking?
Vaporise the hydrocarbon and mix them with steam and heat with a high temeprature
