Chemistry of the Atmosphere

Question 1

% of gases in atmosphere today:

Answer 1

approx. 80% nitrogen
approx. 20% oxygen
less than 1% other gases, e.g. carbon dioxide, water vapour, noble gases

Question 2

What was the first phase of the evolution of the atmosphere?

Answer 2

Volcanic activity

Question 3

What did intense volcanic activity release?

Answer 3

Carbon dioxide, steam, ammonia and methane

Question 4

What was the early atmosphere when volcanic activity took place like?

Answer 4

Mostly carbon dioxide and no oxygen gas

Question 5

What was the second phase of the evolution of the atmosphere?

Answer 5

Oceans, algae and green plants absorb carbon dioxide

Question 6

How where oceans formed?

Answer 6

Water vapour condensed and rained

Question 7

How do oceans remove carbon dioxide from the atmosphere?

Answer 7

Carbon dioxide dissolves in the oceans

Question 8

What did dissolved carbon dioxide in oceans do?

Answer 8

Went through a series of reactions and formed carbon precipitates that formed sediments on the seabed

Question 9

How do algae and green plants reduce the amount of carbon dioxide in the atmosphere?

Answer 9

Through photosynthesis

Question 10

What do marine animals’ shells and skeletons contain?

Answer 10

Carbonates from the oceans

Question 11

What happened to the carbon that organisms took from the atmosphere and oceans?

Answer 11

They became locked up in rocks and fossil fuels after the organisms died

Question 12

How are fossil fuels formed?

Answer 12

Plants, plankton and marine animals die, fall onto seabed, get buried by layers of sediment, become compressed and form sedimentary rocks, oil and gas, trapping carbon within them

Question 13

How is crude oil and natural gas formed?

Answer 13

From deposits of plankton - form reservoirs under seabed when trapped inside rocks

Question 14

What is coal made from?

Answer 14

Thick plant deposits

Question 15

What is limestone?

Answer 15

A sedimentary rock

Question 16

What is limestone made of?

Answer 16

Calcium carbonate deposits from the shells and skeletons of marine organisms

Question 17

What was the third phase of the evolution of the atmosphere?

Answer 17

Green plants and algae produce oxygen

Question 18

What evolved first to produce oxygen?

Answer 18

Algae

Question 19

What did the percentage increase of oxygen allow?

Answer 19

More complex life, like animals to evolve

Question 20

What is released into the atmosphere during combustion of fossil fuels?

Answer 20

Carbon dioxide and water vapour

Question 21

When does incomplete combustion take place?

Answer 21

When there isn’t enough oxygen present

Question 22

What does incomplete combustion release?

Answer 22

Carbon monoxide and particulates

Question 23

What are particulates?

Answer 23

Solid particles of soot or unburnt fuel

Question 24

What can happen if particulates are inhaled?

Answer 24

They can cause respiratory problems - they are small enough to access the airways to the lungs are some are small enough to penetrate the alveoli

Question 25

Why are particulates bad for the environment?

Answer 25

Because they or the clouds they produce reflect sunlight back into space, meaning less light reaches Earth - causes global dimming

Question 26

How can carbon monoxide be reduced?

Answer 26

By a catalytic converter

Question 27

Why is carbon monoxide dangerous in the body?

Answer 27

It can stop your blood from carrying oxygen by binding to the haemoglobin so less oxygen can be transported around the body - lack of oxygen - lead to fainting, coma, death

Question 28

Why is carbon monoxide hard to detect?

Answer 28

It has no colour or smell

Question 29

When is sulfur dioxide released?

Answer 29

During combustion of fossil fuels that contain sulfur impurities

Question 30

How is nitrogen oxide created?

Answer 30

From nitrogen and oxygen in the air reacting because of the heat of burning

Question 31

What happens when sulfur dioxide or nitrogen oxide mix with clouds?

Answer 31

They form dilute sulfuric acid or dilute nitric acid

Question 32

What does dilute sulfuric acid or dilute nitric acid (formed when mixed with clouds) do?

Answer 32

It falls as acid rain - kills plants, damages buildings and statues, makes metal corrode

Question 33

How is sulfur dioxide and nitrogen oxide bad for human health?

Answer 33

If breathed in they can cause respiratory problems

Question 34

How can the production of sulfur dioxide be reduced?

Answer 34

Removal of sulfur from the fuel prior to combustion | Using scrubbers in power stations to remove SO2

Question 35

How can the production of nitrogen oxide be reduced?

Answer 35

Using a catalytic converter to convert the nitrogen oxide into nitrogen gas