C14 the earths resources

Question 1

finite recourses

Answer 1

things that are used up at a faster rate than it can be replaced

Question 2

renewable resources

Answer 2

things that are being constantly made so are being used up at equal rates than it is being replaced

Question 3

sustainability

Answer 3

maintaining the supply of things so we don’t over extract resources for future generations and which doesn’t harm the environment

Question 4

potable water

Answer 4

water that’s safe to drink

Question 5

Why is natural water usually not potable?

Answer 5

because as rain, it absorbs gases from the air and once in contact with the soil it also dissolved substances into it so will naturally contain minerals and microorganisms

we must control the amounts of these particles to meet our water regulations.

Question 6

How can we sterilise water?

Answer 6

• adding chlorine
• adding ozone
• passing it through UV light

Question 7

List two ways of obtaining potable water:

Answer 7

• Sewage treatment
• Desalination

Question 8

sewage treatment

Answer 8

• One way of obtaining potable water is through collecting river water and putting it through multiple processes of filtration, sedimentation and sterilisation (sewage treatment). River water enters the system where it goes through screening to remove large debris from the water. it then enters the first sedimentation tank where heavy solids and sediments sink to the bottom (sludge) which is separated from the lighter effluent. the effluent then goes through aeration, where bacteria is used to do aerobic biological treatment where microbes break down organic matter and other microbes. the sludge undergoes anaerobic digestion, when bacteria converts the sludge into methane gas (which can be used as an energy source) and the waste can be used as fertiliser. the effluent then does a final sedimentation process and is released.

Question 9

desalination

Answer 9

• distillation: where the water is heated to vaporise the water gradually, leaving solid particles (of salt) behind whilst the vapour rises and condenses separately and microorganisms are killed. however this process is energy intensive as it needs lots of heat.
• reverse osmosis: when sea water is pressurised through a partially- permeable membrane to force water to the side with filtered fresh water. this doesn’t require energy for heat but does to generate a high enough pressure, additionally releasing the very salty water produced back into the environment corroded pumps and damages marine life. (bleaching).

Question 10

Explain how you can obtain copper from cabbage: (6)

Answer 10

1. burn the cabbage into ash, this ash copper oxide.
2. in a small breaker mix three spatulas of the ash with 50cm³ of sulfuric acid, this will give us copper sulphate solution.(leachate)
3. filter out excess copper oxide from the solution.
4. half the solution.
5. with one half set an electrolysis circuit up with two graphite electrodes.
6. place the electrodes in the electrolyte and turn the power on to 6V.
7. wait until at the cathode copper forms.
8. place an iron nail in the copper sulphate solution and wait for copper to form due to displacement on the nail.

Question 11

LCA

Answer 11

Life Cycle Assessment is the technique used to assess the environmental impact of an object caused by obtaining the raw material, manufacturing it, using it and returning it to the environment.

Question 12

What factors would help create a complete LCA:

Answer 12

the energy used in:
- obtaining the raw materials
- manufacturing the product
- transportation
- using it
- recycling it