Crude oil and fuels

Question 1

Crude oil

Answer 1

A mixture of a very large number of compounds that comes for reserves in the ground

Question 2

Mixture

Answer 2

Two or more elements or compounds that are not chemically joined together.

Question 3

Hydrocarbon

Answer 3

A molecule made of hydrogen and carbon atoms only.

Question 4

Alkanes

Answer 4

A group of saturated hydrocarbons with the general formula CnH2n+2

Question 5

Saturated

Answer 5

When a hydrocarbon contains as many hydrogen atoms as possible

No double bonds

Question 6

Fractional distillation

Answer 6

A method of separating the different hydrocarbons in crude oil by using the fact that they different boiling points.
•	Highest temperature is at the bottom.
•	Lowest temperature is at the top.
•	Largest molecules at the bottom.
•	Smallest molecules at top.

Question 7

Fraction

Answer 7

A mixture of molecules that will be of similar sized and similar boiling point.

Question 8

Boiling point

How does boiling point change up a fractional distillation tower?

Answer 8

The temperature at which the liquid boils and evaporates or the gas condenses.

Decrease up the tower

Question 9

Volatility

How does volatility change up a fractional distillation tower?

Answer 9

The tendency of a liquid to turn into a gas.
• Smaller Hydrocarbons will be more volatile
• Larger hydrocarbons will be less volatile

Increase up the tower.

Question 10

Viscosity

How does viscosity change up a fractional distillation tower?

Answer 10

How easily a liquid flows.
• Smaller Hydrocarbons will be less viscous
• Larger hydrocarbons will be more viscous

Decrease up the tower.

Question 11

Flammability

How does flammability change up a fractional distillation tower?

Answer 11

How easily a fuel burns.
• Smaller Hydrocarbons will be more flammable
• Larger hydrocarbons will be less flammable

Increase up the tower.

Question 12

Combustion

Answer 12

When a hydrocarbon fuel is oxidised and energy is released. The carbon and hydrogen are oxidised, producing carbon dioxide and water.

Question 13

Acid rain

Answer 13

When sulphur dioxide and nitrogen oxides dissolve in droplets of water in the air and react with oxygen, and then fall as acid rain.

Question 14

Global warming

Answer 14

When carbon dioxide, produced from burning fuels, absorbs energy which is radiated from the earth’s surface and causes a rise in global temperatures.

Question 15

Biofuels

Answer 15

Renewable fuels that are made from animal or plant products.

Question 16

Biodiesel

Answer 16

A biofuel made from oils extracted from plants.

Question 17

Wet Scrubbing

Answer 17

Involves the removing sulfur dioxide after combustion from flue gases in powerstations chimney – reduces production of acid rain

Question 18

Sulfur-free fuel

Ultra-low sulfur fuel

Answer 18

Fuel that has had sulfur removed before combustion – reduces the production of acid rain.