Crude Oil And Products Of Crude Oil Flashcards
What is distillation
Means separating liquids with different boiling points
What is the problem with crude oil
A lot cannot be used for the fuel so all the products of crude oils are made from it
In distillation what happens to the lowest boiling points
It evaporates first, you then collect the vapour and condense it, next you change the boiling point to collect the other fractions
What is fractional distillation
It is when there are many different types of liquids with different boiling points and when they all come out one by one they are called fractions
What do longer chains/bigger chains mean?
Less flammable
Higher viscosity
Less volitile
Boiling and melting point increases
What is at the top of the fractional distillation tower
The smaller molecules which have a lower boiling point will go to the top because it is cooler
What does a molecule formula show
The numbers of each type of atom present
What does fractional distillation depend on
Each molecule having a different boiling point
What is found at the bottom is the fractional distillation tower
The molecule with the highest boiling point will condense here (they are bigger molecules)
What is crude oil a mixture of
Different molecules
Are the molecules in crude oil chemically bonded together?
No
If crude oil is heated what would the last thing to boil off be?
Lubricating oil
Does diesel have larger or smaller molecules than petrol?
Larger
Put the following in order from the top of the fractional distillation tower:
Diesel, bitumen, petrol and kerosene
Petrol
Kerosene
Diesel
Bitumen
What is petrol used for?
Fuel in car engines
How many carbons and hydrogens does ‘ethane’ have
Carbons-2
Hydrogens-6
How many carbons and hydrogens does ‘propane’ have
C-3
H-8
How many carbons and hydrogens does ‘Brobane’ have
C-4
H-10
What is diesel used for
Fuel in Diesel engines and as boiler fuel
What does it mean if the viscosity of a hydrocarbon is low
It means it will be a very runner liquid
How many carbons and hydrogens does ‘Pentane’ have
C-5
H-12
How many carbons and hydrogens does ‘Hexane’ have
C-6
H-14
How many bonds does each carbon atom have
4
Why is it more likely that hydrocarbons with short chains catch fire
Because they don’t stick together and they are more volitile
What is the general formula for alkanes
CnH2n+2
Are alkanes saturated hydrocarbons or unsaturated hydrocarbons
Saturated (contain as much hydrogen as possible)
Explain why the alkanes get thicker and less runny as the length of the chain increases
They will get more tangled and there are week forces of attraction between the molecules. Bigger molecules will have bigger attractions
The longer the alkane molecules the …………….. viscous it is
More
The shorter the alkane molecule the …………. its boiling point
Lower
The shorter the alkane molecule the …………. flammable it is
More
What is organic chemistry
It is the chemistry of carbon compound ( excluding carbon dioxide and carbonates)
What are hydrocarbon?
They are compounds which only contains which carbon and hydrogen
What type of bond do alkanes have
Single
How many carbons and hydrogens does ‘Methane’ have
C-1
H-4
What is a molecule
Two or more atoms joined together
What does a displays formula show
All the atoms and bonds
What is combustion
It means burn
What happens in a combustion reaction
Carbon and water is let of into the atmostphere
What is the general world equation for alkane combustion
Alkane + water = carbon dioxide + water
What is complete combustion
It is when the hydrocarbon burns in plenty of oxygen
What us incomplete combustion
It is when there is not enough oxiygen to completely oxides the carbon to carbon dioxide and so some of soot (unburnt carbon) and carbon monoxide
Why is carbon monoxide dangerous
Because it has no smell or taste, therefore it is hard to detect. Carbon monoxide makes you tired and can eventually kill you. Carbon monoxide stops red blood cells carrying oxygen and this can very quickly lead to death
What is produced when air (nitrogen and oxygen) and fuel (mixture of hydrocarbons with some sulphur compounds)
Carbon dioxide Water Nitrogen Carbon monoxide Nitrogen dioxide Sulphur dioxide Particulates (carbon)
What does carbon dioxide do
If it is in water it makes it acidic which can affect sea life
What do plants absorb
Carbon dioxide
What makes surfaces dirty
When particulate carbon is deposited
What does nitrogen (NO) turn rapidly to
The secondary pollutant NO2
What does sulphur dioxide and nitrogen produce and why is it bad
Produces sulphuric acid
Bad for the plants
What are fuels
They are substances which react with oxygen and rales carbon dioxide
What colour would the flame be to see complete combustion
Blue
Why is incomplete combustion dangerous
Because it produces carbon monoxide which causes death
Why is incomplete combustion a waste of fuel
Because it doesn’t make much energy
Why is incomplete combustion messy
Because it produces soot
How might you tell from the flame produced that combustion is incomplete
Because it will have a smoky yellow flame
What is meant by craking alkanes
Craking is breaking large hydrocarbon molecules (which aren’t very useful) into smaller more useful molecules.
How do you crake alkanes
This is done using high temperatures and catalysts
What are catalysts
things that spend up rections, you have different catalysts for different reactions
What is craking an example of
Thermal decomposition
Why when alkanes are cracked are the always a mixture of alkanes and alkenes
Because there is not enough hydrogens to go around
What are alkanes?
They are made up of chains of carbon atoms surrounded by hydrogen atoms. Different alkanes have chains of different lengths.
What is the symbol for a carbon carbon double bond
C=C
What is the general formula for a alkene
CnH2n
What are alkenes unsaturated
Because they do not contain the maximum amount of hydrogen
What are the first five alkanes?
Methane-natural gas Ethane Propane Butane Pentane
What type of flame do alkenes burn in
A smoky yellow flame
Why is bromine water the best way to see if a substance is an alkane or alkene
Because it is the easiest to see. Alkenes turn the bromine water from and orange to colourless (it is decolourised)
There is more need for ………. chains fractions of crude oil such as ……… than for long chains such as …………..
Shorter
Petrol
Diesel
Give three useful substances which we gat from diesel
Petrol
Ethene
Parrafin
How many carbon and hydrogen atoms does ethene have
C=2
H=4
How many carbon and hydrogen atoms does propene have
C=3
H=6
How many carbon and hydrogen atoms does butene have
C=4
H=8
How many carbon and hydrogen atoms does pentene
C=5
H=10
How many carbon and hydrogen atoms does hexene have
C=6
H=12
What are monomers
The are small reactive molecules which can make polymers. Monomers normally contain carbon carbon double bonds
What are most plastics made of
Alkenes
Plastics are very ……. molecules called ………
Large
Polymers
How are polymers made
By joining together thousands of small molecules called monomers
How does ethene turn into a polyer
When spilt it’s double bonds and join another ethene double bond (which also spits up)
Why is cracking so important
Because hydrocarbons are difficult to vaporise and they don’t burn easily this means they are no good as fuels. However we can break down large hydrocarbons molecules in the process of creaking
How are hydrocarbons craked
Using high temperatures and a catalyst
What is another way to crack a hydrocarbon without using a catalyst
Mixing it in steam and heating it at a high temperature
Why is ethene the smallest possible unsaturated hydrocarbons
Because you need at least 2 double bonds
How do propene molecules and any other alkene molecule join together
The double-bond between the carbon atoms in each molecule ‘opens up’. It is replaced by single bonds to the next opened double bond as thousands of molecules join together
Why is cracking so important
Because hydrocarbons are difficult to vaporise and they don’t burn easily this means they are no good as fuels. However we can break down large hydrocarbons molecules in the process of creaking
Who are hydrocarbons craked
Using high temperatures to vaporise them and pass them over a catalyst
Or
Mixing it with steam and then heating it at a high temperature
Give an example if when the volatility has helped decided what fraction to use
The refinery gas fraction has the shortest molecules, so it has the lowest boiling point in fact it’s a gas at room temperature. This makes it ideal for using as bottled gas. It’s stored under pressure as liquids in ‘bottles’. When the top of the bottle is opens, the fuel vaporises and flows to the burner where it’s ignited.
Why is ethene the smallest possible unsaturated hydrocarbons
Because you need at least 2 double bonds
How do propene molecules and any other alkene molecule join together
The double-bond between the carbon atoms in each molecule ‘opens up’. It is replaced by single bonds to the next opened double bond as thousands of molecules join together
What are crude oils
They are a mixture of many different coumpound. Most of the compounds are hydrocarbon molecules
Explain the bonding in crude oil
There are no chemical bonds between the different parts of a mixture, so the different hydrocarbons molecules in crude oil aren’t chemically bonded to one another. This means that they all keep their original properties, such as their condensing points.
What are the properties of a mixture
They are just a mixture of the properties of the separate parts
How can the parts in a mixture be seperated?
By using physical methods
crude oil is extracted
From the ground to make fuels
What are the first 5 alkene?
Methene Ethene Propene Butene Pentene
What are the bonds like in alkanes?
Single bonds
What are the bonds like in alkenes?
1 double bond
Description of alkanes?
Saturated
Description of alkenes?
Unsaturated
What is the definition for suturates?
They have a single bond
What is the definition for unsuturates?
They have 1 double bond
What is released in incomplete combustion and why?
Carbon monoxide because there is not enough oxygen to burn
What are alkenes and alkanes?
Hydrocarbons
What is fractional distillation used for and what do you do?
To separate crude oil, Heat to vaporise the crude oil The vapour rises Hotter at the bottom than at the top molecules condense at their fraction
How do you know if something is unsaturated?
It turns bromide water colourless
