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Flashcards in C1a Deck (17):

What are the three fossil fuels?

Crude oil, coal, and gas.


What are non-renewable fuels?

Ones which take a very long time to make and are used up faster than they are formed.


Why are fossil fuels finite and non-renewable resources?

Finite because they are no longer being made or being made extremely slowly. Non-renewable because they are used up faster than they are formed.


What is crude oil?

A mixture of many hydrocarbons.


What are the problems associated with the finite nature of crude oil?

All the readily extractable resources will be used up in the future.
Finding replacements.
Conflict between making petrochemicals and fuels.


What does fractional distillation do?

Separate crude oil into useful products called fractions.


Why does fractional distillation work?

Because of differences in boiling points.


What are the fractions obtained from crude oil?

LPG, petrol, diesel, paraffin, heating oil, fuel oils and bitumen.


What does LPG contain?

Propane and butane gases.


How does fractional distillation separate crude oil into fractions?

Crude oil is heated.
The fractionating column has a temperature gradient which is cold at the top and hot at the bottom.
Fractions containing mixtures of hydrocarbons are obtained.
Fractions contain many substances with similar boiling points.
Fractions with low boiling points exit from the top of the fractionating column.
Fractions with high boiling points exit at the bottom of the fractionating column.


In terms of molecular size, intermolecular forces and boiling point, why can crude oil be separated by fractional distillation?

Crude oil can be separated because it consists of a range of hydrocarbons and these molecules vary in chain length. The bigger the hydrocarbon, the stronger the intermolecular force, meaning the larger the force, the higher the boiling point. So crude oil can be separated because the hydrocarbons have different boiling points.


During boiling, what happens to the forces?

Intermolecular forces between molecules break but covalent bonds within the molecule do not.


Describe some of the environmental problems involved in the exploitation of crude oil.

Oil tanker crashes can lead to oil slicks, by huge amounts of oil being released in to the sea - the waves then spreads the oil out.
Damage to wildlife and beaches.


Explain some of the potential environmental problems involved in the transportation of crude oil.

Oil covers sea birds' feathers which stops them being waterproof, meaning the water soaks into feathers and they die of cold.
The detergents used to clean up oil slicks break the oil into tiny droplets and harm wildlife, as they are toxic to marine creatures.


What are the political problems associated with the exploitation of crude oil?

The UK is dependant on oil and gas from politically unstable countries which means they could be cut off at any time, making it harder to get hold off.
There are future supply issues as countries with most oil and gas have power, so they can choose when to supply or not, leading to political conflicts.


Describe cracking as a process.

It needs a catalyst and a high temperature.
It converts large alkane molecules into smaller alkane and alkene molecules that are more useful for making petrol and polymers.


How does cracking help an oil refinery match its supply of useful products such as petrol with the demand for them?

Demand for short chain hydrocarbons such as petrol is higher than the supply obtained from the fractional distillation of crude oil. For large chain hydrocarbons the demand is less than the supply. Cracking of the excess longer chains, forms more short chain hydrocarbons which are used for a multitude of things - the manufacture of plastic, more petrol.