Gcse Chemistry C1: Air Quality

Front 1

What is the atmosphere composed of?

Back 1

Nitrogen

Oxygen

Argon

Small amounts of water vapour, carbon dioxide and other gases

Front 2

What are the relative proportions of the main gases in the air?

Back 2

78% nitrogen

21% oxygen

1% argon, carbon dioxide, water vapour

Front 3

What can affect air quality?

Back 3

Human activity or natural processes (volcanoes) may release other gases or particulates into the atmosphere.

Front 4

How long ago was the Earth formed?

Back 4

4.5 billion years ago

Front 5

What did water vapour condense to form when the Earth cooled?

Back 5

The oceans

Front 6

How did the evolution of photosynthesising organisms add oxygen to and remove carbon dioxide from the atmosphere?

Back 6

Cyanobacteria (early form of simple plant) were able to photosynthesise so took in carbon dioxide and released oxygen into the atmosphere.

Front 7

How was carbon dioxide removed from the atmosphere other than through photosynthesising organisms?

Back 7

It dissolved into the oceans and formed sedimentary rocks and also by the formation of fossils.

Front 8

How has human activity changed the composition of the atmosphere?

Back 8

By adding small amounts of carbon monoxide, nitrogen oxides and sulphur dioxide and adding extra carbon monoxide and small particulates to the atmosphere.

Front 9

What are the problems of pollutants being added to the atmosphere?

Back 9

Some are directly harmful to humans (e.g carbon monoxide reduces oxygen carrying capacity of blood)

Some harmful to the environment (sulphur dioxide and nitrogen dioxide causes acid rain)

Front 10

What is coal mainly made up of?

Back 10

Carbon

Front 11

What are petrol, diesel fuel and fuel oil mainly compounds of?

Back 11

Hydrogen and carbon (hydrocarbons)

Front 12

When fuel burns, what happens to the atoms of carbon/hydrogen from it?

Back 12

They combine with atoms of oxygen in the air to produce carbon dioxide and/or water.

Front 13

What is oxidation?

Back 13

The gain of oxygen by a substance, substance chemically combining with oxygen.

Front 14

What is reduction?

Back 14

The loss of oxygen by a substance

Front 15

When does fuel burn more rapidly?

Back 15

In pure oxygen rather than in air.

Front 16

What happens to the atoms during a chemical reaction?

Back 16

They are rearranged

Front 17

What is meant by conserving mass?

Back 17

During the course of a chemical reaction, the number of atoms of each element must be the same in the products as in the reactants.

Front 18

How is sulphur dioxide produced if the fuel that is burned contains any sulphur?

Back 18

Burning a substance requires oxygen so when fuel containing sulphur is burnt, the sulphur combines with the oxygen to form sulphur dioxide.

Front 19

What does burning fossil fuels in power station and for transport pollute the atmosphere with?

Back 19

Carbon dioxide and sulphur.

Carbon monoxide and particulate carbon (from incomplete combustion).

Nitrogen oxides (from reaction between atmospheric nitrogen and oxygen at high temperatures inside engines.

Front 20

When is nitrogen oxide formed and what does it oxidise to?

Back 20

Formed during the combustion of fuels in the air and oxidises to nitrogen dioxide.

Front 21

Atmospheric pollutants cannot just disappear. Give examples of where they go.

Back 21

Particulate carbon- deposited on surfaces

Sulphur dioxide/nitrogen dioxide- react with oxygen to produce acid rain

Carbon dioxide- used by plants in photosynthesis and dissolves in rain and sea water

Front 22

How can atmospheric pollution caused by power stations that burn fossil fuels be reduced?

Back 22

Using less electricity.

Removing sulfur from natural gas or fuel oil.

Removing sulfur dioxide and particulates from the flue (pipe) gases emitted by coal-burning power stations.

Front 23

How is sulphur dioxide removed from flue gases by wet scrubbing (control devices for removing particles and/or gases from industrial exhaust streams)?

Back 23

Using an alkaline slurry e.g. a spray of calcium oxide and water.

Using sea water

Front 24

What is the only way to produce less carbon dioxide?

Back 24

Burn less fossil fuels

Front 25

How can atmospheric pollution caused by motor vehicle exhaust emissions be reduced?

Back 25

Efficient engines (burn less)

Low sulphur fuels

Catalytic converters

Balance private and public transport use

Legal limits to exhaust emissions (MOT tests)

Front 26

What does a catalytic converter do?

Back 26

Reduce production toxic gases

Use platinum and rhodium catalyst with high SA - increases rate reaction of carbon monoxide and unburnt fuel from exhaust gases with oxygen from the air. Product - carbon dioxide and water- less harmful to the environment.

Front 27

What are the benefits and problems of using biofuel as an alternative to fossil fuels for motor vehicles?

Back 27

Benefits: renewable, made from plants that absorb CO2 as they grow

Problems: still releases CO2 when burnt, more land needed to grow sufficient amounts of plants to use for fuel

Front 28

What are the benefits and problems of using electricity as an alternative to fossil fuels for motor vehicles?

Back 28

Benefits: does not produce waste gases when used

Problems: often comes from power stations that burn fossil fuels, short range before needing to be recharged, recharging takes a long time