C14- The Earth's resources

Question 1

Renewable resource definition and examples

Answer 1

Those that can be replenished in our lifetime as they are used up. Biofuel, solar energy

Question 2

Finite resources definition and examples

Answer 2

Those that can’t be replenished in our lifetime, and will eventually run out. Oil, gas

Question 3

Why is it hard to tell the time left before fossil fuels run out?

Answer 3

There is a lot of uncertainty in the calculations so are estimates

Question 4

Potable meaning?

Answer 4

Water that is safe to drink (not necessarily pure)

Question 5

3 steps to make potable water in the UK

Answer 5

-Choosing appropriate source of fresh water, e.g rivers, lakes
-Pass through filter beds to remove solid particles
-Sterilisation, adding chlorine/ozone or passing through UV light to reduce microbes

Question 6

Why are these sources not suitable for drinking water..
Water from roads?
Estuary close to the sea?
River near factory?

Answer 6

Could contain impurities like oil
High conc of dissolved salts
Could have dissolved toxic chemicals

Question 7

3 factors that make water unpotable

Answer 7

-Large amount of solid particles e.g soil
-High concs of dissolved substances e.g salt
-Disease causing microbes e.g bacteria

Question 8

Key way of sourcing water in hot/dry countries?
2 processes?
Disadvantages?

Answer 8

Desalination
Distillation or reverse osmosis
-Require large amounts of energy, is expensive

Question 9

3 parts to water analysis practical?
How to carry it out?

Answer 9

pH= use universal indicator & colour chart
Solids= record mass of evaporating basin, add 30cm3 of water sample. Heat over bunsen burner until dry then let cool. Record new mass, calc change in mass which = mass of dissolved solids.
Distillation= place water sample in conical flask. Use bung and delivery tube connected to a clamped boiling tube in beaker of ice water. Heat water over bunsen burner until boiling, wait until 1cm3 water in test tube. Then use blue cobalt chloride paper, should turn pink

Question 10

3 types of sewage and what does each one contain?

Answer 10

Sewage- organic matter, harmful microbes
Agricultural- organic matter, harmful microbes
Industrial- organic matter, harmful chemicals

Question 11

How is sewage waste treated?

Answer 11

1. Screening- removes large objects and grit
2. Sedimentation- produces sewage sludge and effluent
3. Effluent= aerobic biological treatment
4. Sewage sludge= anaerobic digestion

Question 12

What happens to effluent and sewage sludge after being treated?

Answer 12

Effluent- released back into environment, e.g rivers
Sludge- used as fertiliser or renewable energy