atmosphere and environment

Question 1

carbon monoxide

Answer 1

• colourless odourless gas
• comes from the incomplete combustion of car engines
• reacts with haemoglobin in blood which reduces the ability of haemoglobin to transport oxygen to the rest of the body

Question 2

sulfur dioxide

Answer 2

• fossil fuels such as crude oil, petroleum, natural gas
• burnt in vehicles, power stations and factories
• irritates the eyes and lungs and cause breathing difficulties
• reacts with water and forms acid rain which corrodes buildings (limestones) and harm aquatic life, plants

Question 3

oxides of nitrogen

Answer 3

• nitrogen combines with oxygen in the air to form nitrogen monoxide, nitric oxide

Question 4

unburnt hydrocarbons

Answer 4

• released in car exhaust fumes and chemical plants

- causes cancer

Question 5

methane

Answer 5

• colourless and odourless gas which is produced by plant and animal matter
• greenhouse gas
• causes global warming

Question 6

ozone

Answer 6

• formed when nitrogen oxide in the air reacts with unburnt hydrocarbons in the presence of sunlight
• forms photochemical smog, irritates the eyes and lungs, causes breathing difficulties
• damages crops

Question 7

how is acid rain formed?

Answer 7

• when acidic air pollutants such as sulfur dioxide and nitrogen dioxide react with water in the atmosphere
• sulfur dioxide dissolves in water to form sulfuorous acid
• in the presence of oxygen in the air it is slowly oxidised to form sulfuric acid

Question 8

what are the effects of acid rain?

Answer 8

• reacts with metals and carbonates like marble and limestone, damage buildings
• leaches nutrients from soil and causes them to die
• produce al3 ions which causes plants to die

Question 9

how do catalytic converters help remove pollutants in vehicle exhaust gases

Answer 9

• hot exhaust gases pass over the platinum and rhodium catalysts in a catalytic converter
• carbon monixide –> carbon dioxide
• oxides of nitrogen –> nitrogen
• unburnt hydrocarbons –> co2 and water

Question 10

flue gas desulfurisation

Answer 10

• cheaper alternative
• as sulfur dioxide passes through a plant it reacts with the suspension of calcium carbonate to form solid calcium sulfite and carbon dioxide gas
• calcium sulfite is further oxidised to from calcium sulfate
• besides calcium carbonate, calcium oxide can also be used

Question 11

what is ozone?

Answer 11

pale blue gas with pungent odour, toxic pollutant

Question 12

importance of

ozone layer

Answer 12

filters out harmful ultraviolet rays, too much UV can cause skin cancer

Question 13

what causes the depletion of ozone

Answer 13

• harmful UV radiation from the sun is absorbed by the protective ozone layer
• propellants like aerosol release CFCs into the atmosphere.
• In the presence of UV radiation CFCs decompose to form chlorine atoms

Question 14

carbon cycle

Answer 14

• mechanism that maintains the level of carbon dioxide in the atmosphere

Question 15

how is co2 added into the atmosphere

Answer 15

• respiration
• combustion of fuels
• decay and bacterial decomposition

Question 16

how is co2 removed from the atmosphere

Answer 16

• photosynthesis

- ocean uptake

Question 17

what are greenhouse gases

Answer 17

gases that trap radiation, reducing the amount of energy lost into space

Question 18

what is the greenhouse effect

Answer 18

solar radiation passes through the atmosphere, reflected into space
warms the earth surface and infrared radiation rises
greenhouse gases trap some heat and warms the earths surface