C9-Chemistry of the atmosphere

Question 1

What formed the Earth’s early atmosphere?

Answer 1

Volcanic activity

Question 2

What was the earth’s early atmosphere made of?

Answer 2

• 95% Carbon Dioxide
• 5% Water and other gases

Question 3

What is our atmosphere made up of today?

Answer 3

• 78% Nitrogen
• 21% Oxygen
• 0.9% Argon
• 0.04% Carbon dioxide
• 0.06% Other gases

Question 4

What led to increased levels of oxygen in the atmosphere?

Answer 4

Plants and algea taking in carbon dioxide and releasing oxygen via photosynthesis

Question 5

Why has carbon dioxide reduced in our atmosphere?

Answer 5

• Photosynthesis by algea and plants converted to glucose and oxygen
• The carbon is transferred to animals as they eat the plants
• Over million of years, the skeletons and shells of huge numbers of marine organisms are built up at the bottom of vast oceans and are buried by sediment
• This forms sedimentary carbonate rocks such as limestone-containing calcium carbonate CaCO₃

Question 6

What causes coal to be formed?

Answer 6

Thick deposits of plant material that died in swamps

Question 7

What caused crude oil and natural gas to be formed?

Answer 7

The remains of plankton deposited in muds on the seabeds

Question 8

What caused the Nitrogen gas to rise in the atmosphere?

Answer 8

Volcanoes producing nitrogen gas

Question 9

What are the symbol equations for methane and ammonia reacting with oxygen? (Don’t need to balance)

Answer 9

• CH₄ + 2O₂ –> CO₂ + 2H₂O
• 4NH₃ + 3O₂ –> 2N₂ + 6H₂O

Question 10

How does the greenhouse effect work?

Answer 10

• Short wave radiation from the sun absorbed by the Earth warming it up
• The Earth emits long wave radiation back into space
• Greenhouse gases reflect some long wave radiation back towards the earth
• This heats up the earth

Question 11

What does the oxidation of N₂ gas in vehicle engines at high temperatures cause?

Answer 11

Nitrogen oxides to be released and therefore acid rain.

Question 12

What does the incomplete combustion of large hydrocarbons in diesel cause?

Answer 12

Carbon monoxide to be released which is a toxic gas

Question 13

What does the incomplete combustion of fossil fuels cause?

Answer 13

Particulates to be released which lead to global dimming.

Question 14

What does the oxidation of sulfur impurities in fossil fuels cause?

Answer 14

Sulfur dioxide to be released that leads to acid rain.

Question 15

What does the complete combustion of fossil fuels cause?

Answer 15

Carbon dioxide to be released that leads to global warming.