DF - inorganic chemistry and the periodic table

Question 1

atmospheric pollutants

Answer 1

CO, CO2, NOx, SOx

Question 2

origin of atmospheric pollutants

Answer 2

particulates, unburnt hydrocarbons

Question 3

greenhouse effect

Answer 3

The earth naturally radiates infra-red radiation out into space. But greenhouse gases in the atmosphere absorb some of this radiation. This is called the greenhouse effect and it keeps the earth warm

Question 4

Origin of Carbon Dioxide, CO2

Answer 4

Burning carbon-based fuels (transport, power stations) is one factor that is causing an increase in the amount of CO2 in the atmosphere.

Question 5

Implication of Carbon Dioxide, CO2

Answer 5

The build-up of CO2 and other greenhouse gases is causing the enhanced greenhouse effect or global warming

this is causing the earth to warm up slowly, which is a huge problem

controlling global warming isn’t easy and needs a sustained effort from countries all around the world

Question 6

Origin of Carbon Monoxide, CO

Answer 6

incomplete combustion, so get carbon monoxide instead of carbon dioxide

Alkanes
CH4 (g) + 1/2O2 (g) –> CO (g) + 2H2O

Cycloalkanes
C4H8 (g) + 4O2 (g) –> 4CO (g) + 4H2O (g)

Alkenes
C4H8 (g) + 4O2 (g) –> 4CO (g) + 4H2O (g)

Alcohols
CH3OH (l) + O2 (g) –> CO (g) + 2H2O (g)

Question 7

Implications of Carbon Monoxide, CO

Answer 7

CO is poisonous

1. the molecules are chemically similar to O2 molecules
2. this means CO can bind to the same sites on haemoglobin molecules in RBC as O2 molecules
3. so less O2 can be carried around the body, so if you breath too much CO in can suffer internal suffocation

Question 8

Origin of unburnt hydrocarbons

Answer 8

engines dont burn all the fuel molecules, some of these come out as unburt hydrocarbons

Question 9

origin of Oxides of Nitrogen, NOx

Answer 9

produced when the high pressure and temp. in a car engine cause the nitrogen and oxygen in the air to react together.

Question 10

Implications of NOx

Answer 10

can cause acid rain

when NOx escapes into the atmosphere its dissolves in the moisture and is converted to nitric acid

• destroys vegetation
• corrodes buildings and statues
• kills fish in lakes

Question 11

Implication of unburnt hydrocarbons and nitrogen oxides, NOx

Answer 11

the hydrocarbons the nitrogen oxides react, in sunlight, to form ground level ozone (O3), this is a component of photochemical smog

• irritate eyes
• aggravate respiratory problems
• cause lung damage

Question 12

Origin of Sulfur Dioxide, SO2

Answer 12

Burning fossil fuels that contain sulfur produces sulfur dioxide

Question 13

Implications of sulfur dioxide, SO2

Answer 13

can cause acid rain

when SO2 escapes into the atmosphere its dissolves in the moisture and converted to sulfuric acid

• destroys vegetation
• corrodes buildings and statues
• kills fish in lakes

Question 14

Origin of Particulates

Answer 14

Particulates are tiny particles of liquid suspended in the air.

Solid particulates, such as carbon, are produced in the burning of fossil fuels in vehicles and power stations

Question 15

Implications of particulates

Answer 15

settle in people’s lungs and cause:

• decreased lung function
• irritation of airways

also contribute to cardiovascular problems which can lead to:

• heart attacks
• strokes

Question 16

what are the biggest sources of air pollutants

Answer 16

• transport
• industry
• power generation

Question 17

Methods of reducing sulfur dioxides, SO2

Answer 17

sulfur dioxide is removed from power station flue (emissions from industrial exhausts and chimneys) gases using calcium oxide

Question 18

Method of reducing particulates

Answer 18

particulates are removed from:

• power station flue gases using wet scrubbers which capture them in water droplets
• some car exhausts using filters

Question 19

Use of catalytic converters

Answer 19

reduce carbon monoxide, unburnt hydrocarbons, sulfur dioxide and nitrogen oxide emissions from vehicles.

Question 20

Method of reducing Carbon Monoxide, CO

Answer 20

oxygenates are added to petrol to help the fuel fully combust

Question 21

What could be done quickly to reduce the problem of pollution

Answer 21

1. governments could change laws
   eg. in UK sulfur and nitrogen oxide emissions from power stations have been reduced as laws about emissions have been tightened
2. new vehicles are not allowed to pollute above a certain level and the yearly MOT inspection included an emissions test. Catalytic converters have been compulsory on new cars in the UK since 1992
3. governments can tax pollution more highly
   eg. raise taxes on fuel, or on highly polluting engines
4. people can reduce the amount of pollution they produce by changing their behaviour
   eg. fewer car journeys or car share

Question 22

What could be done in the long term to reduce pollutants

Answer 22

develop new fuels that cause less polution