The Earth’s Atmosphere Flashcards
What is the purpose of the life cycle assessment?
To look at every stage of a product’s life to assess the impact it would have on the environment
Treatment of fresh water:
> The water needs to be filtered (filter out the large solid bits)
Then the water is sterilised (harmful bacteria is killed using chlorine gas, ozone or UV light)
Treatment of seawater:
- some countries are too dry to use surface or groundwater so use seawater
> must be treated with desalination (takes away mineral components) can be done by desalination
Distillation method:
Test the pH of the water using a pH meter (it should be neutral)
Heat the water up causing it to evaporate and will enter the condenser as steam
In the condenser it will cool into water
Test the pH again to check it’s neutral
Test for hydrogen
Put a burning splint at end of test tube, if there’s hydrogen it will pop
Test for oxygen
Put a glowing splint into a test tube of gas, the splint will relight if oxygen is present
Test for carbon dioxide
Lime water - when carbon dioxide is shaken with limewater it turns cloudy
Test for chlorine
Litmus paper - paper is bleached if chlorine is present
Test for alkenes
Bromine water - bromine water turns colourless if alkene is present
How was the atmosphere formed
Lots of volcanoes erupting and releasing lots of gases
What was the atmosphere like at the beginning?
> mostly carbon dioxide
volcanoes released nitrogen + water vapour which built up in the atmosphere
How were oceans formed?
Water vapour condensing
How did carbon dioxide levels decrease?
> some dissolved into oceans
green plants and algae evolved and absorbed carbon dioxide during photosynthesis
How did oxygen levels rise?
Green plants and algae produced it in photosynthesis
When oxygen levels were high enough, more complex life could evolve
What is the composition of the atmosphere now?
80% nitrogen, 20% oxygen, small amounts of other gases
What are carbon footprints?
A measure of the amount of carbon dioxide and other greenhouse gases released over the full life cycle of something
Why is measuring carbon footprint really hard?
There are so many different factors to consider e.g. you have to consider sourcing the materials, making a product, using the product and the disposal of the product
Consequences of global warming:
- ice caps melting -> rise in sea levels, increased flooding
- changes in rainfall patterns -> areas getting too much or too little water which can affect farming
- more intense and frequent storms
- affecting distribution of species in habitats due to changes in temperature and water availability
What’s of reducing carbon footprints:
- renewable energy sources
- governments could tax companies or individuals based of the amount of carbon dioxide they emit
- governments can put a cap on emissions of all greenhouse gases that companies make
- capturing carbon dioxide before its released into the atmosphere and then storing it deep underground
Why is making reductions of carbon emissions difficult?
- many governments are worried that it will impact the economic growth on communities and many countries don’t want to sacrifice their economic growth meaning it’s hard to make international agreements
- everyone needs to be on board (including all individuals in communities) and it’s hard to get people to make changes if they don’t want to
What gases are released into the atmosphere during complete combustion of fossil fuels?
Carbon dioxide and water vapour
What gases are released into the atmosphere in incomplete combustion?
Soot, carbon monoxide and carbon dioxide
How is soulful dioxide released into the atmosphere?
During the combustion of fossil fuels that contain sulfur impurities - the sulfur in the fuel becomes oxidised
How are nitrogen oxides created?
From a reaction between nitrogen and oxygen in the air, caused by the heat of burning
