AQA GCSE chemistry paper 2

200 million years ago, what was the atmosphere’s composition?

similar to Earth today. 80% N, 20% 02, small amount of other gas mainly c02, noble gas, water vape

What is one theory for the first billion years of the Earth?

surface covered in volcanic activity, releasing gas to form early atmosphere&water vapour condensing to oceans

What was Earths early atmosphere like?

Mars, Venus(mostly c02, virtually no 02

What did volcanoes release in Earths early atmosphere?

gas to form early atmosphere&water vapour condensing to oceans, N(gradually built up), small amount of meth, ammonia

What happened when the oceans were formed by water vapour?

c02 removed from early atmosphere, to mix in water to form carbonate precipitate=sediment on seabed

When did algae first produce oxygen?

2.7 billion years ago, which appeared in atmosphere

What happened over the next billion years after algae?

plant evolve&% of 02 increase to allow animals evolve

What was one way c02 from the atmosphere decreased?

formation of sedimentary rocks&fossil fuel that contain Carbon.

What do greenhouse gases in the atmosphere maintain enough to support life?

temperatures

Main greenhouse gases?

water vapour, c02, methane

What do all particles absorb?

certain frequencies of radiation

What do greenhouse gases not absorb?

incoming short wavelength radiation from sun

What do greenhouse gases absorb?

long wavelength radiation that get reflect from Earth surface

What does greenhouse gases do after long wave radiation reflected from Earth surface?

re-radiate in all direction, including back toward earth

What is long wave radiation?

thermal radiation

What forms of human activity affect amount of greenhouse gases in the atmosphere?

deforestation, burn fossil fuel, creating waste, agriculture

What does burning fossil fuels do?

carbon locked in fuel release as c02

What does agriculture do?

more farm animals produce meth through digest process,

What does creating waste do?

more landfill site, more waste from agriculture=c02&meth released by decomposition of waste

What does an increase in average global temperature equal to?

major cause of climate change

What does global climate change do/affect?

polar ice cap melting, change in rainfall pattern, freq&severity(storm), change in temp/amount of water(habitat)

What does polar ice cap melting mean?

rise in sea level/flood in coastal area&erosion

What does changes in rainfall patterns mean?

amount/timing/distribution=change, cause regions to get a variation of water, along with temp affect region to produce food

What does the frequency and severity of storms mean?

they’ll rise

What does changes in temperature and amount of water available in a habitat mean?

affect wild specie=diff in distribution

What is a carbon footprint?

a measure of amount of c02&greenhouse gas released over full life cycle of something

What can be reduced to decrease the carbon footprint?

emission of greenhouse gases

ways to reduce greenhouse gases?

renew/nuclear energy instead of fossil fuel, use efficient process, govern tax firms/individuals based on amount of greenhouse they emit, govern put cap on emission of all greenhouse gas that firms make, tech that capture c02 produce by burn fossil fuel before released in atmosphere.

What does a lot of waste do that releases methane?

decomposes

What does using more efficient processes help reduce greenhouse gases?

conserve energy&cut waste.

What can governments do after putting cap on emissions of all greenhouse gases that companies make?

sell licenses for emissions up to cap

What can be done to c02 after produced by burning fossil fuels before released into atmosphere is captured by a technology?

stored underground in crack in rock.

Why reductions of carbon footprints is limiting?

carbon capture/storage=new idea(developing), many renew energy tech=expensive, governs worry it impact economic growth, not everyone want to do it if no one else is doing it, even individual have to change their lifestyle(some dont want to)

What is combustion of fuels equal to?

major source of atmospheric pollutants

What do most fuels contain?

carbon, hydrogen, sulfur.

What do gases released into the atmosphere when a fuel is burned include?

c02, h20, carbon monoxide, sulfur dioxide, oxides of nitrogen. Solid particles, unburned hydrocarbon may also be released that form particulates in atmosphere.

What does fossil fuels contain?

hydrocarbons

how are carbon monoxide, soot (carbon particles), sulfur dioxide and oxides of nitrogen produced by burning fuels?

during burning(combustion) C&H in compound not all burnt, because not enough 02=incomplete combustion.

What are the products of complete combustion?

c02, water vape

What is carbon monoxide?

toxic gas, colourless, odourless(not easily detected)

Sulfur dioxide and oxides of nitrogen cause respiratory problems in humans and cause acid rain.

Particulates cause global dimming and health problems for humans.

What does sulfur dioxide and oxides of nitrogen cause?

respiratory problems in humans and cause acid rain.

What do particulates cause?

global dimming and health problems for humans

What do humans use the Earth’s resources for?

warmth, shelter, food, transport.

What do natural resources added to by agriculture provide?

food, timber, clothing, fuels.

What are finite resources from the Earth processed to provide?

energy and materials.

What do urban lifestyles and industrial processes produce?

large amounts of waste water that require treatment before being released into environment

What do sewage and agricultural waste water require?

removal of organic matter and harmful microbes

What does Industrial waste water require?

removal of organic matter and harmful chemicals.

What sewage treatment include?

screening/grit removal, sedimentation to produce sewage sludge and effluent, anaerobic digestion of sewage sludge, aerobic biological treatment of effluent.

What are copper ores now becoming?

scarce

What are new ways of extracting copper from low-grade ores

phytomining, bioleaching.

What does phytomining, and bioleaching avoid?

traditional mine methods of digging, moving/disposing of large amounts of rock.

What does phytomining use to absorb metal compounds?

plants

How are plants used in phytomining?

plants are harvested, then burned to produce ash that contains metal compounds.

What does Bioleaching use to produce leachate solutions that contain metal compounds.

bacteria