Unit 1 Gcse Chemistry

Front 1

What is the atmosphere?

Back 1

The atmosphere is a thin layer of gases surrounding the Earth

Front 2

What is the composition of the atmosphere?

Back 2

78% nitrogen
21% oxygen
1% argon

Front 3

What's the first stage of the evolution of the atmosphere?

Back 3

The early atmosphere was created by volcanic activity and consisted mainly of carbon dioxide and water vapour

Front 4

What's the second stage of the evolution of the atmosphere?

Back 4

As the Earth cooled, the water vapour condensed and this process formed the oceans

Front 5

What's the third stage of the evolution of the atmosphere?

Back 5

Simple photosynthetic organisms evolved in the oceans, adding oxygen to the atmosphere and removing carbon dioxide

Front 6

What's the final stage of the evolution of the atmosphere?

Back 6

Some carbon dioxide was removed due to it dissolving in the oceans and forming sedimentary rocks and fossil fuels

Front 7

What do pollutants harm?

Back 7

Environment and health

Front 8

How does carbon dioxide harm the environment?

Back 8

It's a greenhouse gas, it traps heat in the Earth's atmosphere

Front 9

How do nitrogen oxides harm the environment/humans?

Back 9

1)They cause acid rain
2)Cause breathing problems and can make asthma worse

Front 10

How does sulfur dioxide harm the environment?

Back 10

It causes acid rain

Front 11

How do particulates harm the environment/humans?

Back 11

1)Make buildings dirty
2)Can make asthma and lung infections worse if inhaled

Front 12

How does carbon monoxide harm humans?

Back 12

It prevents the blood from carrying oxygen. It can be fatal

Front 13

What does 20ppb of sulfur dioxide mean?

Back 13

It means that for every 1000000000 molecules of air, 20 molecules will be sulfur dioxide

Front 14

Give an example of why you should repeat measurements

Back 14

The concentration of nitrogen oxides from cars may change depending on the time of day, amount of traffic and the weather.

Front 15

What do repeat measurements allow chemists to do?

Back 15

They'll allow them to calculate a mean which will give a good estimate of the true value of the concentration of the pollutant

Front 16

What are three natural processes that remove carbon dioxide from the atmosphere?

Back 16

1)Photosynthesis
2)Dissolves in the oceans
3)Forms sedimentary rocks and fossil fuels

Front 17

What are elements made of?

Back 17

Tiny particles called atoms

Front 18

How do compounds form?

Back 18

Compounds form when the atoms of two or more different elements chemically combine

Front 19

What does the formula show?

Back 19

It shows different elements that make up a compound and the number of atoms of each element in one molecule

Front 20

What does "mass is conserved" mean?

Back 20

No atoms are lost or made in a chemical reaction, so the total number of products and the total number of reactants are the same

Front 21

What is combustion?

Back 21

Combustion (burning) is a chemical reaction.

Front 22

When does combustion occur?

Back 22

Combustion occurs when a fuel reacts with oxygen and energy is released.

Front 23

Because the fuel reacts with oxygen, combustion is what?

Back 23

A type of oxidation

Front 24

What is coal mainly made up of?

Back 24

Carbon

Front 25

What does one atom of carbon and one molecule of oxygen produce?

Back 25

It produces carbon dioxide

Front 26

When does complete combustion occur?

Back 26

Complete combustion occurs when there's enough oxygen present for a fuel to burn completely

Front 27

What compounds do petrol, diesel and fuel oil mainly consist of?

Back 27

Hydrocarbons

Front 28

What atoms do hydrocarbons contain?

Back 28

They contain only hydrogen and carbon atoms

Front 29

What do hydrocarbons produce when burned in air?

Back 29

They produce carbon dioxide and water

Front 30

When does incomplete combustion occur?

Back 30

Incomplete combustion occurs when a fuel is burned and there's not enough oxygen

Front 31

What could be produced by incomplete combustion (depending on the amount of oxygen present)?

Back 31

Carbon particulates (C) or Carbon monoxide (CO)

Front 32

Where does incomplete combustion occur?

Back 32

Incomplete combustion occurs in car engines

Front 33

What do exhaust emissions contain?

Back 33

They contain carbon particulates and carbon monoxide as well as carbon dioxide

Front 34

What can coal contain when burned?

Back 34

Coal can contain sulfur, so sulfur dioxide is released when burned

Front 35

What is SO2?

Back 35

Sulfur dioxide

Front 36

What can happen during the combustion of fuels at high temperatures?

Back 36

It can cause nitrogen in the atmosphere to react with oxygen, which causes nitrogen monoxide (NO)

Front 37

What happens to nitrogen monoxide when it's oxidised?

Back 37

It produces nitrogen dioxide (NO2)

Front 38

What causes NOx?

Back 38

When NO and NO2 occur together

Front 39

How can power station emissions be reduced?

Back 39

1)Using less electricity
2)Removing sulfur and toxic chemicals from gas, coal and oil before burning
3)Using alternative renewable energy sources

Front 40

Give examples of renewable energy sources.

Back 40

1)Wind
2)Solar
3)Hydroelectric
4)Wave
5)Geothermal ect.

Front 41

How can you remove sulfur dioxide from chimneys?

Back 41

By wet scrubbing with either a spray of calcium oxide and water or using seawater

Front 42

How can car emissions be reduced?

Back 42

1)Using low-sulfur fuel in a car with a modern fuel-efficient engine
2)Legal limits for exhaust emissions, enforced by MOT
3)Using public transport
4)Cars with catalytic converters

Front 43

What do catalytic converters do?

Back 43

They reduce carbon monoxide and nitrogen monoxide in the engine exhaust gases

Front 44

Carbon monoxide + oxygen -->...

Back 44

Carbon dioxide

Front 45

Nitrogen monoxide + carbon monoxide -->...

Back 45

Nitrogen + carbon dioxide

Front 46

Why is it difficult to reduce emissions?

Back 46

Because we would need to burn fewer fossil fuels. This would be very hard since the population of the world is increasing every year and so is the demand of energy

Front 47

What can be used instead of fossil fuels to power cars?

Back 47

Biofuel

Front 48

What's a disadvantage with biofuel?

Back 48

It uses up valuable farmland

Front 49

How is combustion a type of oxidation?

Back 49

Because the fuel reacts with oxygen

Front 50

What does the term hydrocarbon mean?

Back 50

A hydrocarbon is a compound made only from hydrogen and carbon

Front 51

Give three ways in which to reduce power station emissions

Back 51

1)Using less electricity
2)Removing sulfur from the fuel being used
3)Removing sulfur dioxide and particulates from the gases released by the power station

Front 52

Give four ways to reduce pollution pollution from cars.

Back 52

1)More efficient engines
2)Low-sulfur fuels
3)Catalytic converters
4)Public transport
5)Walking or cycling
6)Legal limits for emissions

Front 53

Explain how NOx gases are formed

Back 53

Atmospheric nitrogen is oxidised by atmospheric oxygen at high temperatures to form nitrogen monoxide (NO),which is further oxidised to form nitrogen dioxide (NO2)