2.3 The Wider Impact Of Chemistry

Question 1

Problems with energy: Discuss Fossil and biomass fuels

Answer 1

• cannot be replaced shortly term
• we will run out within out lifetimes
• CO2 emmisions have increased by a third in the last 100yrs
• result in global warming and climate change

Question 2

Problems with energy: Discuss Carbon neutrality

Answer 2

• trees or crops replanted to replace fossil fuels burnt
• if a biomass like sugar cane is grown and burnt as fuel the net change in CO2 levels should be neutral

Question 3

Problems with energy: Discuss nuclear power

Answer 3

• can be problems disposing of radioactive waste
• fusion of hydrogen is more efficient than uranium however it takes a huge amount of heat and pressure

Question 4

Problems with energy: Discuss solar power

Answer 4

• efficiency varies with sun exposure and can be as little as 10%

Question 5

Problems with energy: Discuss hydrogen power

Answer 5

• involves the electrolysis of water
• it does not produce any harmful gases
• it is costly in terms of the energy needed for the electrolysis process.

Question 6

What are the aims of green chemistry?

Answer 6

1. Use renewable materials
2. Use renewable sources
3. Use methods with high atom economy
4. Use catalysts so lower temp and pressure can be used
5. Avoid toxic materials
6. Prevent pollution
7. Avoid waste or produce renewable byproducts