The Atmosphere

Question 1

How is ozone formed

Answer 1

Uv light splits diatomic oxygen Monatomic oxygen produced reacts with diatomic oxygen atoms to form ozone

Question 2

How is ozone deconstructed

Answer 2

Uv light splits ozone molecule into monatomic and diatomic oxygen atoms

Question 3

Types of uv radiation in order of wavelength high to low

Answer 3

Uv A
Uv b
Uv c

Question 4

Effect of uv a

Answer 4

Cause sunburn
Synthesis of vitamin A

Question 5

Effect of uv b

Answer 5

Damages organic molecules such as dna

Question 6

Effect of uv c

Answer 6

Would be rapidly fatal but absorbed by ozone

Question 7

What are main points of Rowland molina hypothesis to say why cfcs are bad

Answer 7

Persistence of cfcs
Dissociation by uv and the release of chlorine
Reaction of chlorine and oxygen to prevent formation of ozone

Question 8

What is a cfc

Answer 8

A chlorofluorocarbons is an organic molecule containing chlorine, fluorine and carbon atoms

Question 9

What are cfcs used for

Answer 9

Refrigerator
Aerosol propellants
Bubbles in polystyrene

Question 10

Why were CFCs useful

Answer 10

Boiling point below ambient so liquified easily
Good solvent
Not flammable
Not toxic

Question 11

How do CFCs destroy ozone

Answer 11

React with uv and split releasing chlorine radicals
Then cl reacts with ozone to form o2 and clo
Which reacts reacts with oxygen and takes it out the ozone cycle and forms chlorine and o2 again
This cycle repeats meaning ozone can’t form

Question 12

Methods for evidence of ozone depletion

Answer 12

Ground based data collection
Satellite surveys
Air samples from stratosphere

Question 13

Why is ozone depletion highest over Antarctica

Answer 13

Low stratospheric temps forming ice clouds for chemical reactions to take place
Winds rotate forming a polar vortex with little mixing of air maintaining the low temps

Question 14

How has ozone been restored

Answer 14

International agreement to reduce use of CFCs
Seek alternatives

Question 15

What protocol helped ozone restoration

Answer 15

Montreal protocol 1987

Question 16

Examples of alternative processes to reduce ozone depletion

Answer 16

Trigger sprays reduce aerosol propellants
Roll on deodorants

Question 17

Examples of alternative materials to reduce ozone reduction

Answer 17

Hcfcs used instead as it breaks down sooner
HFCs replaced these to reduce chlorine production

Question 18

What are PANs

Answer 18

Peroxy acetyl nitrates

Question 19

How does North Atlantic conveyer belt work

Answer 19

Warm water from tropical Atlantic Ocean travels north east towards north west Europe due to
Friction from prevailing winds that direction and water in north east Atlantic cooling and sinking drawing in warm water to replace it

Question 20

Changes in North Atlantic conveyor belt due to climate change

Answer 20

Increased temperature causes land ice in Greenland to melt and go in sea
It dilutes salt water this reduces density so doesn’t sink as much which reduces flow rate so cooling occurs in north west Europe