C10 Using the Earth's resource sustainably

Question 1

Rocks

Answer 1

Building Materials

Question 2

Fossil Fuels

Answer 2

clothes fibres, plastics, warmth

Question 3

Plants and animals

Answer 3

timber, medicine, food

Question 4

fresh and seawater

Answer 4

fertiliser, drinking water

Question 5

air

Answer 5

oxygen, fertiliser

Question 6

sunlight & wind

Answer 6

electricity

Question 7

sustainable development

Answer 7

utilising resources to meet needs of people now without preventing people in future from meeting their needs

Question 8

unsustainable practices

Answer 8

throwing away materials
fossil fuels for transport
fossil fuels for electricity

Question 9

sustainable practices

Answer 9

recycling
biofuels for transport
renewable energy

Question 10

reuse over recycling

Answer 10

recycling requires energy to melt down and recast, using fossil fuels

Question 11

life cycle assessment

Answer 11

• extraction of raw materials
  requires heat to extract copper
• manufacture
  heat required to mold
• usage
  transport
• disposal
  melting if recycled

Question 12

water containing no microbes or dissolved substances

Answer 12

pure water

Question 13

water containing no dissolved substances

Answer 13

potable water

Question 14

other types of water

Answer 14

sea water
fresh water
ground water
waste water

Question 15

potable water from fresh water

Answer 15

filter to remove solids, sterilise with chlorine/ozone/UV to kill microbes

Question 16

potable water from sea water

Answer 16

distillation
water boils into steam and salt does not, water vapor condenses in seperate chamber

reverse osmosis
uses high pressure to push water molecules through semipermeable membrane while salt does not pass

Question 17

waste water treatment

Answer 17

• grit removal
• primary sedimentation tanks where organic matter sinks to bottom as sludge
• sludge seperated and anaerobically digested by bacteria
• CH4 released by bacteria burned for heat & electricity
• effluent from PST taken to aerating tank
• air is bubbled through effluent and good microbes kill harmful microbes
• cleansed effluent transferred to final settling tanks
• returned to environment after sterilisation

Question 18

ores

Answer 18

rocks from which a metal can be extracted from for profit

Question 19

high reactivity vs low reacitvity extraction

Answer 19

electrolysis / carbon displacement

Question 20

composition of different alloys

Answer 20

steel = iron + carbon
high C = stainless
low C = cars

gold alloy = gold + silver
jewelry

brass
copper + zinc
kills bacteria

bronze
copper + tin
statutes

Question 21

corrosion

Answer 21

metals are damaged by reaction with water and/or oxygen

Question 22

rusting

Answer 22

corrosion of iron/steel

iron + water + oxygen -> rust

Question 23

methods of prevention

Answer 23

protective layers
stop water/oxygen from touching material e.g. paint on car

sacrifical protection
more reactive metal corrodes instead of iron
zinc blocks welded to hull of a ship

galvanising
protective + sacrifical
dip iron in molten Zn

Question 24

extraction of copper by phytomining (using plants)

Answer 24

earth is running out of copper ore

leaching -> acid
bioleaching -> enzyme

leach cabbage ash with H2SO4 50cm^3

TWO METHODS

electrolysis
check for brown metal on the graphite electrode

displacement
place large iron nail in copper compound solution, look for brown on nail

Question 25

soda lime glass

Answer 25

sand + sodium carbonate + calcium carbonate general usage brittle and hard

Question 26

borosilicate glass

Answer 26

sand + boron trioxide lab usage (beakers) melts less easily so cracks less easily

Question 27

ceramics

Answer 27

wet clay is baked in a furnace

Question 28

composite definition

Answer 28

made from a reinforcement + matrix (binds material)

Question 29

composite examples

Answer 29

(reinforcement + matrix) fibre-glass glass fibre + polymer natural wood cellulose fibre + lignin MDF wood fibre + adhesive carbon fibre carbon fibre + polymer concrete stone/sand + cement water

Question 30

thermosoftening vs setting

Answer 30

setting has covalent bonds between polymer chains, softening does not

Question 31

haber process

Answer 31

n2(g) + 3h2(g) -> 2nh3 (g) at equilibrium, exothermic reaction reversible nitrogen obtained from air hydrogen obtained from natural gas unreacted n2/h2 reused in reaction 450ºc is compromise rate >/ yield< /cost> 100atm is compromise rate> / yield> / cost> Fe catalyst yield unchanged, rate >, lowers cost (temp/pressure necessary less)

Question 32

NPK fertilisers

Answer 32

replace the natural NPK salt manufactured (acid + base) or mined manufactured: ammonium, calcium (phosphate rock) mined: potassium

Question 33

single vs triple superphosphate

Answer 33

calcium phosphate + calcium sulfate calcium sulfate

Question 34

RPA10

Answer 34

50cm3 seawater in measuring cylinder, put in conical flask and bung with delivery tube leading to boiling tube in ice bath heat water test pH using universal indicator, put on watchglass over water bath and evaporate some and find mass of dissolved solid seawater is alkaline rainwater is acidic