C1 - Air Quality Flashcards
What percentage of the air is nitrogen?
78%
What percentage of the air is oxygen?
21%
What percentage or the air is argon and other rare gases?
Less than 1%
What percentage of the air is carbon dioxide?
0.04%
How can we find the percentage of oxygen in air?
By passing air over heated copper
When was the earth’s atmosphere formed?
About 4 billion years ago
Describe what happened during the forming of the atmosphere?
Volcanoes + Clouds -> Oceans -> Photosynthesis -> Shellfish Sedimentation -> Evolution -> Fossil Fuels
- Volcanoes released CO2 and Water Vapour
- Earth cooled and oceans formed from the condensed water vapour as it rained for thousands of years
- Tiny bacteria formed in the oceans and photosynthesised to create oxygen.
- Shellfish took in CO2 to make shells and when they died they became part of the sediment. Over billions of years thick layers of chalk and limestone built up
- Animals evolved to breathe oxygen instead of CO2 and the animals which took in CO2 died and became fossils and the fossil fuels we have today
- People burn the fossil fuels and release CO2 back into the air
What did scientists think made up the early atmosphere 60 years ago?
Ammonia and Methane
What was the early atmosphere actually mainly made of?
Carbon dioxide
Pollutants
Gases which are harmful to us and the environment
Give Examples of pollutants
Nitrogen oxides, Carbon monoxide, Carbon dioxide and Sulphur dioxide
Why is Carbon monoxide dangerous?
It reduces the amount of oxygen blood can carry
Solid particulates
Small solid particles which float in the air
2 Examples of solid particulates?
Soot and Volcanic ash
By what percentage have carbon dioxide levels risen in the last 50 years?
25%
Which two pollutants make acid rain?
Sulphur dioxide and nitrogen dioxide
What units are small amounts of Carbon Dioxide measured in?
ppm or parts per million
What units are pollutant gases such as Carbon monoxide, nitrogen oxides and sulphur dioxide measured in?
ppb or parts per billion
Correlation
A link between a factor and an outcome.
What causes Sulphur dioxide pollution and what does it cause?
Volcanoes and power stations burning fossil fuels cause it and it causes acid rain
What causes Nitrogen monoxide/ dioxide pollution and what does it cause?
Lightning and car engine air cause it and it results in acid rain
What causes Carbon monoxide pollution?
Forest fires and car exhaust fumes
What causes Carbon dioxide pollution and what does it cause?
Fires, volcanoes, respiration and burning fossil fuels cause it and it contributes to global warming
Hydrocarbons
Substances made up of hydrogen and carbon atoms
What is the word equation for complete hydrocarbon combustion?
Hydrocarbon + Oxygen -> Carbon + Water + Energy
What is the word equation for incomplete hydrocarbon combustion?
Hydrocarbon + oxygen -> Carbon Monoxide + Water
What’s the difference between complete and incomplete combustion?
Complete combustion has lots of oxygen whereas incomplete does not
Oxidation
When oxygen is added to a substance
Reduction
When oxygen is removed from a substance
Combustion
Burning
An example of an oxidation reaction
Combustion
Reactants
The substances which are being reacted together
Products
The substances which are formed during a chemical reaction
Insoluble
Cannot dissolve in water
Soluble
Can dissolve in water
Solution
A substance which has had something dissolved into it
What are the word and chemical equations for the formation of sulphur dioxide
Sulphur + Oxygen = Sulphur dioxide
S + O2 -> SO2
Which fossil fuel contains the most sulphur?
Coal
What does acid rain do?
It lowers the pH when it falls on land or enclosed water harming living things or eroding carbonate rocks.
Indirect pollutants
Pollutants which don’t affect humans directly such as acid rain
What happens when a fuel burns but there is not enough air available to burn it? 2 outcomes
- Carbon monoxide is formed
* Bits of soot are made making the surfaces they land on dirty
How are pollutants removed from the air?
- Particulate carbon settles on surfaces making them dirty
- Sulphur and nitrogen oxides react with water and oxygen to produce a mixture of sulphuric acids and nitric acid in rain (Acid rain)
- Carbon dioxide is used by plants for photosynthesis
- Carbon dioxide dissolves in rain water and oceans
Mean
An average where all results are added and divided by the frequency of results
Range
The difference between high and low results
Outliers
Data samples which do not seem to fit the pattern or break laws of science and must be incorrect
Electrostatic filters
Equipment used in power stations to remove solid particulates
Describe both methods of flue gas desulphurisation or “wet scrubbing”
- Limestone is heated -> Calcium oxide (lime) + Carbon dioxide
Lime + Water -> Alkaline slurry
Alkaline slurry + Sulphur dioxide + Oxygen -> Calcium Sulphate (Gypsum)
Gypsum can be used to make wall plaster - Reacting sea water with sulphur dioxide to make a sulphate and carbon dioxide
How to reduce fossil fuel usage?
- Using alternative energy sources such as solar or wind power
- Improving building insulation or wearing warmer clothing to reduce usage of Central heating
- Walking, biking or using public transport
- Recycling
- Using Eco friendly or energy efficient appliances
Biofuels
Fuels made from plants
Examples of biofuels:
- Wood chips
- Palm oil
- Alcohol made from sugar
Carbon neutral
If something is Carbon neutral, it’s usage produces as much carbon dioxide as it takes in
Disadvantage of biofuel usage
•Large areas of land are needed to grow biofuels and this land could be used to plant food
Advantages of biofuel usage
- They’re carbon neutral
* It produces less carbon dioxide than coal for the same amount of energy
Sustainable
Efficient enough to be carried on for a long period of time and not affect future generations
Advantage and disadvantage of using hydrogen gas as a fuel
ADV: it doesn’t produce CO2
DISADV: It uses more energy to extract hydrogen than it makes
How to reduce air pollution from vehicles:
- Use cars less, especially for shorter journeys
- Using cleaner fuels and removing pollutants from exhausts
- Making public transport cheaper, more frequent and available in more places
What do Catalytic converters do?
They allow pollutants to react and create safer gases
Equations for the reaction which takes place in catalytic converters
Carbon monoxide + Nitrogen monoxide -> Carbon dioxide + Nitrogen
2CO + 2NO -> 2CO2 + N2
What gases are in our air?
Nitrogen, Oxygen, Carbon Dioxide, Argon and other rare gases
