Atmospheric chemistry

Question 1

How much oxygen is there in the atmosphere as a percentage?

Answer 1

21

Question 2

How much nitrogen is there in the atmosphere as a percentage?

Answer 2

78

Question 3

How much CO2 is in the atmosphere as a percentage?

Answer 3

0.03

Question 4

How much noble gases are in the atmosphere as a percentage?

Answer 4

One

Question 5

How much H2O is in the atmosphere percentage?

Answer 5

It varies

Question 6

What are the uses of oxygen?

Answer 6

Respiration, combustion? Oxyacetylene torches

Question 7

What is the most reactive gas in air?

Answer 7

Oxygen

Question 8

Is nitrogen very reactive?

Answer 8

Nitrogen is quite unreactive as it has a triple bond

Question 9

What are the uses of nitrogen?

Answer 9

Food packaging and production of ammonia by the harbour process

Question 10

What are the two methods of nitrogen fixation?

Answer 10

Nitrogen fixed and bacteria and lightning

Question 11

How does nitrogen fixing bacteria convert atmospheric nitrogen to compounds that can be used by plants?

Answer 11

In the soil or in the roots of peas and beans, the nitrogen infection and bacteria convert nitrogen gas into nitrates for plants to take in their roots

Question 12

What do plants use nitrates for?

Answer 12

To make protein for growth

Question 13

How does lightning change atmospheric nitrogen compounds that can be used by plant plants?

Answer 13

When when lightning strikes the energy in lightning causes nitrogen and oxygen in the atmosphere to react

Question 14

Explain using equations how lightning changes atmospheric nitrogen to nitrogen compounds

Answer 14

NO + O2—>2NO
2NO +O2 —> 2NO2
2NO2 + H20 —> HNO2 + HNO3

Question 15

What does the nitrogen cycle show?

Answer 15

It shows the way in which nitrogen circulates in nature between air plants and animals

Question 16

Name some in organic carbon compounds

Answer 16

Carbon monoxide and carbon dioxide

Question 17

What is carbon monoxide

Answer 17

It is colourless odourless and tasteless
It has no effect on limitless or universal indicator

Question 18

How does carbon monoxide form?

Answer 18

It is formed by the incomplete combustion like by insufficient oxygen supply such as in cigarettes and vehicle engines

C+1/2O2 —-> CO

Question 19

How does carbon dioxide form?

Answer 19

By the combustion of fossil fuels
Respiration in plants and animal cells
Fermentation of glucose by yeast and anaerobic conditions

Question 21

Describe carbon dioxide

Answer 21

It is older, less colourless and tasteless and acidic

Question 22

Why is carbon monoxide bad?

Answer 22

It is a accumulative poison it binds to haemoglobin and prevents it working so can’t carry oxygen around in the body

Question 23

What are the uses of carbon dioxide?

Answer 23

Photosynthesis
Fire extinguishers
Dry ice

Question 24

What is the carbon cycle?

Answer 24

It is the way in which carbon circulates in nature between the air plants and animals

Question 25

What is the greenhouse effect?

Answer 25

It is the trapping of the suns heat by particular gases in the atmosphere

Question 26

Explain how the greenhouse effect is caused

Answer 26

Short ultraviolet rays from the Sun passed through the earths atmosphere and are absorbed by the Earth However, the Earth heats up and radiate heat back out in the form of long infrared rays which cannot pass through some gases in the atmosphere like carbon dioxide and water vapour so they increase the temperature of the earth

Question 27

What is the greenhouse factor?

Answer 27

It measures the greenhouse effect close by a gas relative to the same amount of carbon dioxide So carbon dioxide is given a value of one

Question 28

What is the value of CFC’s in the greenhouse factor?

Answer 28

Between 21,00 and 25000

Question 30

What is the greenhouse factor of nitrogen oxide?

Answer 30

160

Question 31

What is the greenhouse factor of carbon dioxide?

Answer 31

One as everything is measured relative to the same amount of carbon dioxide so it has to be one

Question 32

What is the greenhouse factor of vapour water vapour?

Answer 32

0.1

Question 33

What is the greenhouse factor of methane?

Answer 33

30

Question 34

What are the effects of the greenhouse effect?

Answer 34

Violent weather Melting of polar ice caps Raising sea levels

Question 35

Do we need the greenhouse effect?

Answer 35

Yes, we need the greenhouse effect as it is essential for life as it keeps the planet warm allowing life to exist. However we cannot have the enhanced greenhouse effect.

Question 36

What is pollution?

Answer 36

It is any harmful addition to the environment

Question 37

What is acids rain

Answer 37

It is rain that has a pH of less than 4.5

Question 38

What are the causes of acid rain?

Answer 38

Sulphur dioxide and sulphur trioxide

Question 39

How do sulphur dioxide form?

Answer 39

It is formed from the burning of sulphur and fossil fuels and from volcanoes S+02—->SO2 It is an acidic oxide and dissolves in water to form sulfurous acid SO2 + H20—> H2SO3

Question 40

How does sulphur trioxide form?

Answer 40

Sulphur dioxide can be oxidised by O2 in the air just for Emma sulphur trioxide SO2+ 1/2O2 —-> SO3 Sulphur trioxide dissolved the water forms sulphuric acid SO3 + H2O—-> H2 SO4

Question 42

Why are sulphurous acid and sulphuric acid bad?

Answer 42

They contribute to acid rain

Question 44

What is another cause for acid rain that isn’t oxides of sulphur?

Answer 44

Oxides of nitrogen such as nitrogen dioxide and nitrogen monoxide

Question 45

How do oxides of nitrogen form?

Answer 45

Oxides of nitrogen produced from car exhaust and power stations as nitrogen gas react with oxygen in the air nitrogen monoxide Nitrogen monoxide reacts with oxygen in the air forming nitrogen dioxide The nitrogen dioxide dissolves in water to form a mixture of nitrous acid and nitric acid

Question 46

What are the environmental effects of acid rain?

Answer 46

Corrosion of limestone buildings and metal Damages trees Causes aluminium to lead out of soil into rivers causing fish to die

Question 47

What material can be used in power stations to remove sulphur dioxide from chimney gases

Answer 47

Limestone in a process called scrubbing

Question 48

What is the process called in scrubbing of chimneys to remove sulphur dioxide?

Answer 48

Scrubbing

Question 49

Explain scrubbing using an equation

Answer 49

CaC03+ SO2–> CaCO3 + CO2 So the sulphur dioxide is removed and carbon dioxide is produced instead

Question 50

What is ozone?

Answer 50

It has the molecular formula 03

Question 51

What does the ozone do?

Answer 51

It screens us from harmful effects of UV radiation by absorbing the ray of the sun. UV radiation causes sunburn which can lead to skin cancer.

Question 52

How is ozone formed?

Answer 52

It is formed in the stratosphere by photodissociation of oxygen E.g. the breakdown of oxygen by light

Question 53

Explain photodissociation of oxygen in the formation of ozone

Answer 53

02—>O.+O. An oxygen molecule is broken down into two oxygen free radicals by light energy 02+O—->O3 Oxygen molecules in the stratosphere react with a free radical of oxygen to form ozone

Question 54

What damage is the ozone layer?

Answer 54

CFC’s

Question 55

What does CFC stand for?

Answer 55

Chlorofluorocarbons

Question 56

What do CFC’s do to damage the ozone layer?

Answer 56

They break down and release chlorine free radicals which attack ozone in the stratosphere

Question 57

Where do you find CFC’s?

Answer 57

Aerosol cans EG deodorant Fridges Air-conditioning units

Question 58

Using equations explain how CFC attacking the ozone

Answer 58

CCL3F+ UV—-> CCL2F + CL. 03 + Cl. —> 02 + ClO. ClO. + O —-> Cl. + O2