Chemistry 1: Air Quality Flashcards
1
Q
Atmosphere
A
Thin layer of gas surrounding a planet
2
Q
Mixture
A
One or more elements or compounds mixed together but not chemically joined, so they can be separated out fairly easily
3
Q
Gas
A
State of matter in which atoms or molecules that’s based far apart and spread out to fill the available space
4
Q
What does air consist of
A
- mainly nitrogen, oxygen and nitrogen
* contains small amounts of water vapour and carbon dioxide
5
Q
Molecule
A
Two or more atoms held together by strong chemical bonds
6
Q
PArticles
A
Particles are very small, so in gases there is lots of empty space between gas molecules. This means gases can be squeezed into a smaller volume, like in a bike tire
7
Q
What does oxygen react with
A
Oxygen gas reacts with most metals to make solid metal oxides
8
Q
Where do we find the largest percentage of oxygen in the air
A
Passing over heated copper
9
Q
When was the earth atmosphere formed?
A
About 4 billion years ago by gases given out by volcanoes. Volcanoes release huge amounts of carbon dioxide water vapour. They also only released lava and dust
10
Q
Lava
A
Molten rock (magma) from beneath the Earth’s surface when it erupts from a volcano
11
Q
Name the different processes that have almost removedall of the carbon dioxide that was in the early atmosphere, leaving the air with composition we have today:
A
- 4 billion years ago the earths atmosphere was very hot
- as the earth called, oceans formed from the condensed water.
- about 3 billion years ago simple bacteria like creatures evolved to use photosynthesis
- this removes carbon dioxide is from the air, and release oxygen, allowing animals to evolve.
- carbon dioxide was removed by plants and animals dying and becoming buried
- over millions of years some of the buried material becomes fossil fuels
- carbon dioxide dissolved in oceans reacts with salts to form insolvable calcium carbonate.
- this forms sediment which become buried and cemented to form sedimentary rocks
12
Q
Dissolve
A
To be solvable in water
13
Q
Fossil fuels
A
Fuel such as coal, oil or natural gas, formed millions of years ago from dead plants and animals
14
Q
How ideas have changed over time
A
- sixty years ago many scientist thought the early atmosphere was largely ammonia and methane
- recent rock composition discoveries showed early ideas were not correct, and the early atmosphere was largely carbon dioxide
15
Q
Methane
A
A gas with molecules carbon and hydrogen; greenhouse gas
16
Q
How has human activity changed air quality
A
Humans are changing the gases in the atmosphere by burning fuels. Fuels are used in factories, power stations, for transport and in homes
17
Q
Pollutant
A
Hatful substance in the environment
18
Q
How are pollutants dangerous?
A
Pollutants are harmful to the environment and to our health for example carbon monoxide reduces the amount of oxygen blood can carry
19
Q
Examples of pollutants
A
Carbon monoxide. Nitrogen oxides and sulphur dioxide
20
Q
Carbon monoxide
A
Poisonous gas whose molecules consist of once carbon and one oxygen atom CO
21
Q
Nitrogen oxides
A
Gaseous molecules containing nitrogen and oxygen atoms according to the formula NOx, where x=1,2 etc; these pollutants are formed due to high temperatures created by the combustion of fossil fuels
22
Q
What happens when fuels are burnt?
A
Releases carbon dioxide and solid particulates that float in the air, e.g. Carbon (soot). Particulars are also released naturally as ash from volcanoes
23
Q
Carbon
A
An element that combines with others, such as hydrogen and oxygen m, to form many compounds in living organisms
24
Q
Carbon dioxide information
A
- in the last 50 years the amount of carbon dioxide in the air has increased by 25%
- is linked to climate change, by acting as a ‘greenhouse’ trapping heat in the atmosphere
- Human activity, like burning down forest to make more farmland, increases carbon dioxide and particulates
25
Correlation
A link between two factors that shows they are related, but one does not necessarily cause the other; a positive correlation shows that as one variable increases the other also increases; a negative correlation shows that as one variable decreases
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Effects of Air pollution
* Levels are high, more deaths from asthma, heart disease and lung disease occur. There is a correlation between air quality and health.
* is more of s problem in large cities, such as Mexico City and Beijing. Some countries, e.g. The UK, have made loads to try to improve air quality
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Acid rain
Rainwater which is made more acidic by pollutant by acidic gases
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Which gases make acid rain
Sofa dioxide and nitrogen dioxide a pollutants that make acid rain, which damages plants and animals, are asthma triggers for some people
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What are small amounts of carbon dioxide measured in
Small amounts of carbon dioxide in the air are measured in parts per million (ppm). One ppm means that there is 1 g of pollutants substance in 1,000,000 g of air
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Which gases are measured in parts per billion (PPB)
The other pollutant gases – carbon Monarch side, nitrogen oxides and sofa dioxide – are measured in parts per billion (PPB).
31
What is the amount of pollutant gases used for
The amount of pollutant gases are measured in a quality monitoring stations throughout the UK. The data is transmitted automatically to a central computer for analysis
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What do we need for correlation
Data
33
What is needed for any fuel to burn
Oxygen
34
Hydrocarbon
Compound containing only carbon and hydrogen
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Word equation for hydrocarbon burning
Hydrocarbon fuel + oxygen-> carbon dioxide +water (+energy)
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Oxidation
Chemical process that increases the amount of oxygen in a compound; the opposite of reduction
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Reduction
A process that reduces the amount of oxygen in a compound, or remove all oxygen from it – the opposite of oxidation
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Combustion
Process in which substances react with oxygen releasing heat
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What differences pure oxygen make to combustion
Gases in the atmosphere can be separated. Pure oxygen makes fuels burn more rapidly at higher temperatures. One example is in the Oxy fuel welding torch, which to melt steel
40
Atom
The basic ' Building block' of an element which could not be chemically broken down
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What do you atoms do
Items do not change. In Chemical reactions Adams get rearrange to make new substances. Atoms of non-metal elements joined to form molecules
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Molecule
Two or more atoms held together by strong chemical bonds
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Elements
Substance made out of only one type of atom
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Compounds
Substance composed of two or more elements which are chemically joined together for example H2O
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Reactants
Chemicals that react together in a chemical reaction
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Products
Chemicals produced at the end of a chemical reaction
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Mass in a reaction
Maths is conserved in a reaction because all the atoms in the reactants I just rearranged in the products. For examples, all the carbon atoms in all the fossil fuel ever burnt are still present, but in different forms
48
Burning so far, what gas is created
Solid yellow so far burns and makes a colourless gas called sulfur dioxide. So far is insoluble but so far dioxide dissolves in water to make an acid solution
49
What do fossil fuels contain
What's the fuels contain small amount of so far from the plants and animals that formed them.
50
Word equation for sulfur burning
Sulfur+ oxygen -> sulfur dioxide
| S + O -> SO2
51
Coal
Coal often contains the most sulfur so burning coal can give off the most Sulfur dioxide than other fossil fuels
52
Acid rain explanation
In the 1970s people noticed forests and aquatic life in ponds with Dying. Scientists were able to use data to explain that sulfur dioxide cause acid rain. Acid rain lowers the pH when it falls on land or enclosed water, harming living things or eroding carbonate rock. Acid rain does not affect humans directly, so it is called and indirect pollutant
53
How are pollutants formed mainly
Power stations and transport make most pollution because they burn the most fuel. Electricity production and transport has increased over the last century. Sulfur dioxide is made if the fuel contains sulfur. Carbon dioxide it is always formed when fuels burn.
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What happens if there is not enough for the fuel to burn
If not enough is available to burn the fuel:
- poisonous carbon monoxide is made
- bits of solid carbon (it) called particulates are made, making surfaces the land on dirty
55
How else are pollutants formed (nitrogen)
Car engines make nitrogen oxides when nitrogen and oxygen from the air react at high temperatures. This contributes to acid rain. Air-quality measurements need repeating many times because results vary. On dry, hot, com days, Appalachians can be trapped in cities.
56
When is carbon monoxide formed
Carbon monoxide particulate carbon off from during incomplete combustion (insufficient oxygen). Only in the last 50 years have scientists discovered how different air pollutants form, and how they react with the air to produce smog, acid rain and climate change
57
When is nitrogen monoxide formed
* nitrogen monoxide (NO) is formed in furnaces and engines at a temperature of about 1000°C
* when nitrogen monoxide is released into the atmosphere it calls. It then reacts with more oxygen to form toxic nitrogen dioxide a brown gas
* NOx damages buildings, contribute to acid rain, and can affect health.
58
When are pollutants removed from the air
pollutants are removed from the air when:
- Particulate carbon settles on surfaces, making them dirty
- sulfur and nitrogen oxides reacts with water and oxygen to produce a mixture of sulphuric acid and nitric acid in the rain (acid rain)
- carbon dioxide is used by plants for photosynthesis
- carbon dioxide dissolves in rainwater and in oceans
59
Smog
Air-pollution that is caused four example by vehicle emissions and industrial fumes
60
How do climate scientists measure pollutants
* climate scientists take the mean of many measurements for each pollutant. The mean is a good estimate of the true value.
* The range is the difference between high and low results.
* Air quality results vary for several reasons. Potential outliers could at Chili be valid data, and removing them could lead to mistakes.
61
Ways in which to improve power stations
* . Reducing electricity reduces fossil fuel use in power stations
* New electrical products use less electricity, but some is wasted if they are left on standby
* turning all and gas makes less Salford dioxide then burning coal
* sulfur can be removed from oil and gas before it is band, but it is harder to remove from coal
* Power stations are developing ways of reducing pollution by cleaning waste gases
* Power stations can remove solid particle it from electrostatic filters
* sulfur dioxide can be removed from waste gases by flue gas desulfurisation
62
Flue gas desulfurisation
Industrial process whereby sulfur is removed from Waste gases
63
Methods use to remove Salford dioxide from power station waste gases are:
To ' wet scrubbing' methods used to remove sulphur dioxide from power station waste gases are:
1. Using an alkaline slurry of calcium oxide (lime) and water to make gypsum (calcium sulphate), which can be sold as plaster
2. Using seawater, and natural alkaline which absorb sulfur dioxide
64
What happens to carbon dioxide when we burn less fossil fuels
* Burning less fossil feels reduces the amount of carbon dioxide (CO2) gas released
* ways to reduce our use of fossil feels include: using alternative energy sources; improving building installation; walking, cycling, using public transport
65
One alternative to using fossil fuels
One alternative to using fossil feels is biofuels, which are made from plants. Examples of woodchips, palm oil and alcohol made from sugar
66
Biofuel
Fuels such as wood, ethanol or biodiesel, obtained from living plants
67
Pros of using biofuels
* biofuels are 'carbon neutral' – When they are burned they're release the same amount of carbon dioxide is done the plants originally took from the air to grow
* large areas of land I needed to grow biofuels. The land could be used for growing food
* gas produces less carbon dioxide and call for the same amount of energy released
* fossil fuels are not renewable, so they are not a sustainable source of energy
68
Sustainable
Resource or process that will still be available to future generations
69
How can appellation from vehicles be reduced
* using cars less, especially for short journeys
* using cleaner fuels and removing pollutants from exhausts
* making public transport cheaper, more frequent and available in more places
* modern vehicles have more efficient engines that use less fuel
70
Catalytic converters
A device fitted to vehicle exhaust to reduce the level of nitrogen oxides and burnt hydrocarbons emitted
71
What do catalytic converters contain
A platinum catalyst that allows pollutant gases to react with each other
72
Word equation for catalytic converters and what happens here
Carbon monoxide+ nitrogen monoxide-> nitrogen+ carbon dioxide
• carbon monoxide games oxygen so it is oxidised
• nitrogen monoxide loses oxygen to its is reduced
73
How is the Catalytic converter is exhaust emissions controlled
* low-sulfur fuels are needed as so for damages the catalyst. Using those sulfur feels also reduces sulfur dioxide emissions
* legal limits for exhaust missions are in force by strict MOT tests
74
Electric cars
* Electric cars do not give out pollutant gases when being used, but the electricity produced by fossil fuel power stations use for charging does.
* research continues into improving batteries and improving charging times. Few charging points are available at present
