C1c

Question 1

How much of the air is oxygen

Answer 1

21%

Question 2

How much of the air is nitrogen

Answer 2

78%

Question 3

How much of the air is carbon dioxide

Answer 3

0.035%

Question 4

How do deforestation and a rising population influence the composition of air

Answer 4

Deforestation: reduces the amount of trees which then reduces photosynthesis, which removes CO2 from the atmosphere so there is more
Rising population: more people to respire which produces CO2 when they breathe out, more space needed to live so more deforestation etc.

Question 5

How did the present day atmosphere form over millions of years. Give 2 theories

Answer 5

early volcanoes release water vapour and carbon dioxide (degassing)
water vapour condensed to form oceans
CO2 dissolves in ocean waters
nitrogen relatively increased due to its lack of reactivity
photosynthetic organisms development decreased CO2 and increased oxygen levels

Question 6

What happens when nitrogen is exposed to the high temperatures in an internal combustion engine

Answer 6

It reacts with oxygen to make oxides of nitrogen

Question 7

What is the balanced symbol equation for how a catallytic converter removes CO and NO from exhausts

Answer 7

2CO + 2NO = N2 + 2CO2