🔴🔸2.3 -the Wider Impact Of Chemistry

Question 1

Define carbon neutrality

Answer 1

Although combustion does generate co2 this is offset by the fact that the fuel such as biomass or sugar cane has absorbed the same value of co2 in being made by photosynthesis
:: carbon neutral

Question 2

What is energy needed for?

Answer 2

Industry, transport, electricity and domestic heating

Question 3

Name renewable sources of energy

Answer 3

Wind 
Water 
Combustion of biomass 
Geothermal energy 
Nuclear 
Solar energy

Question 4

What has the co2 concentration risen to in past 100 years

Answer 4

From 300ppm to 400ppm

Question 5

What does co2 cause

Answer 5

Global warming via greenhouse effect

Question 6

How is carbon neutrality achieved?

Answer 6

Replanting trees and sugar cane to match the value being burnt so that the co2 consumed in photosynthesis = co2 generated in combustion

Question 7

What % of energy may be produced by nuclear energy?

Answer 7

20%

Question 8

How is nuclear energy generated

Answer 8

Neutron aides fission or uranium in which less than 1% of mass is converted into energy by equation E=mc squared

Question 9

What is a problem of nuclear power

Answer 9

Produces radioactive waste that needs to be correctly stored/disposed

Question 10

Name a better alternative to nuclear fission which is being developed?

Answer 10

Fusion of hydrogen to form helium, only producing water, but not currently possible

Question 11

What efficiency can solar panels generate?

Answer 11

Over 10%

Question 12

Name one way we can use less energy in reactions

Answer 12

Using an effective catalyst and lower temperatures

Question 13

What are the principles of green chemistry (8)

Answer 13

• prevent waste
• increase atom economy
• use safer methods, chemicals and solvents
• increase energy efficiency
• use renewable materials
• use catalysts
• prevent pollution accidents
• design for biodegradation.

Question 14

Name a method of using raw materials

Answer 14

Feedstocks use renewable raw materials such as palm oil for making biodiesel

Question 15

Name a better solvent and it’s advantage

Answer 15

Using liquid waste carbon dioxide under pressure is a residue fee solvent e.g for decaffeinating coffee beans

Question 16

Name a way of reducing toxins and increasing % yield

Answer 16

Simvastatin (cholesterol reducing drug) is made from cheap raw materials using an enzyme made from E. coli and avoids multiple step synthesis using toxic reagents and giver higher yield

Question 17

How can you prevent toxic nitrogen oxides in car/Fidel exhausts?

Answer 17

By adding ammonia to give redox reaction

4NH3 + 3NO2 —> 3.5N2 + 6H2O