topic 8: fuels and earth science

Question 1

acid rain

Answer 1

rain that is acidic due to gases, such as sulfur dioxide, reacting with water vapour in the clouds. sulfur dioxide is produced from the burning of fossil fuels which contain sulfur impurities.

Question 2

alcanes

Answer 2

the most common hydrocarbon found in crude oil

Question 3

alkenes

Answer 3

alkenes are hydrocarbons with a double bond between two of the carbon atoms in their chain, causing them to be unsaturated

Question 4

catalytic cracking

Answer 4

long chain hydrocarbons are heated to turn them into a gas. the vapour is then passed over a hot powdered aluminium oxide catalyst. the long chain molecules split apart on the surface of the catalyst.

Question 5

climate change

Answer 5

a change in global climate patterns largely believed to be caused by the increase in concentration of carbon dioxide in the atmosphere

Question 6

cracking

Answer 6

a process that involves breaking down larger hydrocarbons to produce smaller more useful molecules. cracking can be done by catalytic cracking or steam cracking

Question 7

combustion

Answer 7

the burning of a substance in oxygen causing energy to be transferred to the surroundings as heat and light. during combustion, the carbon and hydrogen in the fuels are oxidised.

Question 8

crude oil

Answer 8

a finite resource found in rocks,l it is the remains of an ancient biomass consisting mainly of plankton that was buried in mud. most of the compounds in crude oil are hydrocarbons

Question 9

finite resource

Answer 9

a resource which will one day run out, being used up faster than created

Question 10

fossil fuel

Answer 10

natural fuels, such as coal and gas, formed in the past from the remains of living organisms

Question 11

fractional distillation

Answer 11

a process shed to separate a mixture of liquids. the liquids have different boiling points so can be separated into different fractions within a fractionating column