Topic 8: Fuels and Earth Science

Question 1

What is crude oil?

Answer 1

A complex mixture of lots of different hydrocarbons (mostly alkenes)

Question 2

Is crude oil a finite resource?

Answer 2

Yes

Question 3

What are hydrocarbons?

Answer 3

Compounds that only contain hydrogen and carbon atoms

Question 4

What happens as the length of the hydrocarbon chain increases?

Answer 4

Boiling point increases
Viscosity increases
Ease of ignition decreases

Question 5

What is complete combustion?

Answer 5

A reaction that occurs when a fuel reacts with plenty of oxygen

Question 6

What is the complete combustion reaction?

Answer 6

Hydrocarbon + oxygen —> carbon dioxide + water

Question 7

Why are hydrocarbons used as fuels?

Answer 7

When they combust, they release a lot of energy

Question 8

What is a homologous series?

Answer 8

A family of molecules which have the same general formula and share similar chemical properties e.g. alkanes

Question 9

What is fractional distillation?

Answer 9

A process used to separate the hydrocarbons in crude oil into fraction according to their boiling points
Each fraction has different uses

Question 10

How does a fractionating column work?

Answer 10

1. Crude oil is heated until most of it has evaporated
2. Longer hydrocarbons have higher boiling points so condense near the bottom of the column
3. Shorter hydrocarbons have lower boiling points so condense near the top of the column

Question 11

What are the fractions of crude oil (starting with the fraction produced at the top of the column)?

Answer 11

Gases
Petrol
Kerosene
Diesel oiI
Fuel oil
Bitumen

Question 12

What are gases used for?

Answer 12

Domestic heating
Cooking

Question 13

What is petrol used for?

Answer 13

Car fuel

Question 14

What is kerosene used for?

Answer 14

Aircraft fuel

Question 15

What is diesel oil used for?

Answer 15

Fuels cars and trains

Question 16

What is fuel oil used for?

Answer 16

Fuels ships and power stations

Question 17

What is bitumen used for?

Answer 17

Surfacing roads and roofs

Question 18

What fractions of crude are non renewable?

Answer 18

Petrol
Kerosene
Diesel oil

Question 19

What is cracking?

Answer 19

Breaking down long chain, saturated hydrocarbons (alkanes) into shorter, more useful molecules

Question 20

Why is cracking done?

Answer 20

There is a higher demand for fuels with shorter carbon chains
Shorter hydrocarbons are more useful

Question 21

What is the equation for cracking?

Answer 21

Long chain alkane —> shorter chain alkane + unsaturated alkene

Question 22

How is cracking done?

Answer 22

Done by heating the alkane with an aluminium oxide catalyst

Question 23

What do fossil fuels contain?

Answer 23

Hydrocarbons
Sulphur impurities

Question 24

What does combustion of fossil fuels release?

Answer 24

Gases and particles which pollute the air

Question 25

What are the products of incomplete combustion that pollute the air?

Answer 25

Carbon monoxide + Carbon (soot) + Carbon dioxide + Water vapour

Question 26

When does incomplete combustion of hydrocarbons occur?

Answer 26

When there isn’t enough oxygen for complete combustion to occur

Question 27

What is the effect of carbon monoxide?

Answer 27

Binds with the haemoglobin in the blood This causes there to be a lack of oxygen being transported in the body This can lead to fainting, coma or even death

Question 28

Properties of carbon monoxide?

Answer 28

Colourless Scentless

Question 29

What is the effect of carbon (soot)?

Answer 29

Causes respiratory problems Reduces air quality Makes building looks dirty

Question 30

Where does sulfur dioxide come from?

Answer 30

From when sulfur impurities in fossil fuels react during combustion

Question 31

What effect does sulfur dioxide have?

Answer 31

Acid rain This causes damage to trees, statues and buildings Lakes also become acidic and plants and animals die

Question 32

Where do oxides of nitrogen come from?

Answer 32

Reactions between nitrogen and oxygen in the air which are caused by the heat of burning fuels e.g. in car engines

Question 33

What is the effect of oxides of nitrogen?

Answer 33

Acid rain This causes damage to trees, statues and buildings Lakes also become acidic and plants and animals die BECAUSE OXIDES MIX WITH CLOUDS TO FORM ACIDS

Question 34

What are advantages of hydrogen as a fuel for vehicles?

Answer 34

Very clean - only waste product is water Obtained from a renewable resource (water), so won’t run out Can be obtained from the water produced by the cell when used in fuel cells

Question 35

What are disadvantages of hydrogen as a fuel for vehicles?

Answer 35

Need a special, expensive engine Hard to store Manufacturing hydrogen is expensive, often uses energy from fossil fuels

Question 36

What was the composition of the earths early atmosphere?

Answer 36

Lots of carbon dioxide Water vapour Very little oxygen Some other gases

Question 37

Why was the earths early atmosphere like this?

Answer 37

Due to volcanic activity that released gases

Question 38

What happened after the earth cooled?

Answer 38

Water vapour condensed and formed oceans

Question 39

What did the formation of oceans lead to? Why?

Answer 39

Decrease in CO2 levels Because CO2 gas dissolved in the oceans

Question 40

What happened after the oceans formed?

Answer 40

Green, primitive, photosynthesising plants and algae then developed

Question 41

What did the evolution of green plants lead to? Why?

Answer 41

Decreased CO2 levels Increased O2 levels This was due to photosynthesis as photosynthesis absorbs carbon dioxide from the air and produces oxygen

Question 42

What is the composition of today atmosphere (with the percentages)?

Answer 42

78% nitrogen 21% oxygen Less than 1% of carbon dioxide, water vapour and noble gases

Question 43

What is the test for oxygen?

Answer 43

Glowing splint test: 1. Glowing split placed into a test tube 2. If the splint relights, oxygen gas is present

Question 44

What are the 3 greenhouse gases?

Answer 44

Carbon dioxide Water vapour Methane

Question 45

What is the greenhouse effect?

Answer 45

When greenhouse gases in the atmosphere absorb long wavelength radiation and re-radiate it in all directions, including back towards Earth, helping to keep the earth warm

Question 46

What do greenhouses: not absorb, absorb and re-radiate?

Answer 46

Don’t absorb: short wavelength radiation from the sun Absorb: long wavelength radiation Re-radiate: long wavelength radiation

Question 47

How has the increasing human population impacted global warming and climate change?

Answer 47

There’s more greenhouse gas emissions

Question 48

Why have greenhouse gas emissions increased?

Answer 48

Fossil fuels are being burnt for energy - more CO2 released Deforestation - less CO2 removed by photosynthesis Cattle farming - more methane produced

Question 49

What have increasing levels of greenhouse gases been linked to?

Answer 49

Global warming

Question 50

What is global warming?

Answer 50

A type of climate change that can cause other types of climate change

Question 51

What are the consequences of climate change?

Answer 51

Flooding due to melting of polar ice caps causing sea levels to rise Changing rainfall patterns

Question 52

What has happened over the years due to greenhouse gases?

Answer 52

Temperature has increased

Question 53

What are the two ways of reducing CO2 and greenhouse gas emissions?

Answer 53

1. Individuals 2. Governments

Question 54

How can individuals reduce carbon dioxide and greenhouse gas emissions?

Answer 54

Walking or cycling instead of driving Turning down central heating Eating less meat

Question 55

How can governments reduce carbon dioxide and greenhouse gas emissions?

Answer 55

Use legislation and financial incentives e.g. congestion charge Fund research into new energy sources that are renewable and better for the environment

Question 56

How to remember the fractions of crude oil in order?

Answer 56

Green Peas Kill Diamond Fusions Bitch