C10 Using resources 2

Question 1

Potable water

Answer 1

Water that is safe to drink but not pure it has a specific level of dissolved substances

Question 2

How is potable water produced in the UK from fresh water

Answer 2

Water is passed through filter beds to remove different sized insoluble molecules
Water is then sterilised to kill microbes with UV light or chlorine

Question 3

How is it produced from salt water

Answer 3

Reverse Osmosis through a partially permeable membrane
Desalination through distillation
Both are expensive

Question 4

How is waste water cleaned for potable use

Answer 4

Water is passed through a mesh screen
to remove large bits

Chemicals are added to make solids and
microbes stick together to form
sediment and sink

There is then anaerobic digestion of sewage sludge

The water is then sterilised with chlorine to kill any microbes left.

Question 5

How is glass and metals recycled

Answer 5

Glass is crushed then melted to form new glass

Metal is melted and added to other metals for example excess steel is added to iron production

Question 6

Thermosoftening polymers

Answer 6

When heated they melt.
Due to:
Weak intermolecular forces between the chain
Chains are easy to seperate
Lower tempearatures
Less heat energy is needed to break the chains

Question 7

Thermosetting polymers

Answer 7

They contain chains with cross links that do not melt when heated but the object hardens