Atmosphere And Oxygen Test Flashcards
What are the four main gases in the atmosphere?
Nitrogen, oxygen, carbon dioxide, argon
What are the % of gases in the atmosphere?
Nitrogen - 78%
Oxygen - 21%
Carbon dioxide - 0.04%
Argon - 0.9%
What are the three components in the fire triangle?
Oxygen, fuel, heat
What is oxygen?
A reactive gas
What are metal oxides and non metal oxides?
Basic, acidic
What are the tests for water?
Cobalt chloride paper turns from blue to pink
Or
Anhydrous copper (ll) sulfate turns white to blue
What is the test for carbon dioxide?
Turns limewater cloudy/milky/chalky
What forms when an element reacts with oxygen?
An oxide forms
What are four reasons to explain why levels of carbon dioxide has decreased?
It’s used as a reactant in photosynthesis
It’s trapped in fossil fuels
CO2 is dissolved into the oceans, which forms carbonate rocks through the CO2 reacting with metal oxides
Skeletons and shells of marine organisms build at the bottom of the ocean and are covered with layers of fine sediment. Under the pressure caused by by these layers the deposits formed sedimentary carbonate rocks e.g limestone (calcium carbonate)
Why have levels of oxygen increased?
Oxygen is the waste product of photosynthesis
2.7 billion years ago bacteria and simple organisms such as algae evolved
Algae uses energy from the sun to make there own food by photosynthesis
Why did levels of nitrogen increase?
Ammonia + oxygen —> nitrogen + water
Methane + oxygen —> carbon dioxide + water
Nitrogen is a very stable element, therefore it built up in the atmosphere
Why did levels of water decrease?
It is a product of photosynthesis
What is the process of fractional distillation?
First the air is cooled to -200c, and the solid carbin dioxide and water is removed. The remaining liquid is fed into the bottom of the fractionating column which is warmer at the bottom than the top. Oxygen and argon have higher boiling points so they remain as liquids and are piped off at the bottom of the column. The temperature at the bottom of the column is higher than the boiling point of nitrogen so it boils rises up the column and is piped off as a gas at the top.
How can you find out the % of oxygen in the air?
What are the reactions with phosphorus and copper?
