7.5 Gases In The Atmosphere Flashcards Preview

GCSE Chemistry 1.7 Our Changing Planet > 7.5 Gases In The Atmosphere > Flashcards

Flashcards in 7.5 Gases In The Atmosphere Deck (15)
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How were fossil fuels originally formed?

Animals are the plants that absorbed carbon dioxide and much of the carbon ended up in plant and animal remains as sedimentary rocks and fossil fuels


How was limestone originally formed?

Shells and skeletons of marine organisms


What do fossil fuels contain and where do they come from?

Fossil fuels contain carbon and hydrogen from plants and animals


Name 2 forms that carbon became locked up in

•as fossil fuels
•as sedimentary rocks


Name 2 ways that sedimentary rocks were formed

•formed from animal and plant remains as they contained carbon
•carbon dioxide dissolved in the ocean and formed insoluble carbonate compounds that were deposited on the seabed as sedimentary rocks


What % of the air today is nitrogen?

78% nitrogen


What % of the air today is oxygen?

21% oxygen


What gases make up the final 1% of the earths air?

•carbon dioxide
•water vapour
•other gas traces (noble gases)


How can we separate the gases in the air and why?

By fractional distillation because the gases in the air have different boiling points


What are the desired products of the fractional distillation of air?

•pure oxygen
•liquid nitrogen


How does the fractional distillation of air work?

The air is cooled to below -200*c and fed into a fractional distillation column, the column gets cooler as you move up it, where the different gases can be separated. Further distillation is needed to separate argon and oxygen


What parts of the animals and plants remains make up the fossil fuels and which parts make up the sedimentary rocks?

Fossil fuels: soft tissues
Sedimentary rock: bones, teeth, shells


When ammonia reacts with oxygen, what are the products?

Nitrogen and water


When methane reacts with oxygen, what are the products?

Carbon dioxide and water


Where did a lot of the carbon dioxide end up in the early atmosphere?

Taken up by plants for photosynthesis