Properties and Uses of Crude Oil Flashcards
The different fractions of crude oil have what?
Different properties and its all down to their structures.
What is crude oil mostly?
Alkanes .
What are ALL the fractions of crude oil?
Hydrocarbons called alkanes.
What are alkanes made up of?
Chains of carbon atoms surrounded by hydrogen atoms.
What do different alkanes have?
Chains of different lengths.
What are the first 4 alkanes?
Methane - natural gas.
Ethane.
Propane.
Butane.
What is the formula for methane?
CH4.
little 4
What is the formula for ethane?
C2H6.
little 2 and 6
What is the formula for propane?
C3H8.
little 3 and 8
What is the formula for butane?
C4H10.
little 4 and 10
What do the straight lines represent on the alkane diagrams?
A covalent bond.
How many bonds do carbon atoms form?
4 bonds.
How many bonds do hydrogen atoms form?
1 bond.
What does saturated mean?
That all the atoms have formed bonds with as many other atoms as they can.
What is the general formula for alkanes?
CnH2n+2.
What does the 2n stand for?
2 times the amount of carbons the alkane has.
- The shorter the molecules…
The more runny the hydrocarbon is and the less vicious.
- The shorter the molecules…
The more volatile they are.
Meaning they turn into a gas at lower temperatures.
- The shorter the molecules…
The lower the temperature at which that fraction vaporises and condenses and the lower the boiling point.
- The shorter the molecules…
The more flammable the hydrocarbon is.
The uses of hydrocarbons depends on what?
Their properties.
The volatility helps decide what?
What the fraction is used for.
What fraction has the shortest molecules?
The refinery gas fraction so it has the lowest boiling point.
What is the refinery gas fraction?
A gas at room temperature.
What is the refinery gas fraction ideal for?
Using bottled gas.
Its stored under pressure as liquid in ‘bottles’.
When the tap on the bottle is opened the fuel vaporises and flows to the burner where it’s ignited.
What does the petrol fraction have?
Longer molecules so it has a higher boiling point.
What is petrol ideal for?
Its a liquid so its ideal for storing in the fuel tank of a car.
It can flow to the engine where its’ easily vaporised to mix with the air before it is ignited.
What also helps decided how hydrocarbons are used?
The viscosity.
What are the really gloopy viscous hydrocarbons used for?
Lubricating engine parts and covering roads.
Summarise what short chain hydrocarbons are.
Less vicious.
More volatile.
Easier to ignite.
