More getting metals from rocks

Question 1

what is a metal ore?

Answer 1

a rock which contains enough metal to make it worthwhile extracting the metal from it

Question 2

in many cases the ore is…

Answer 2

an oxide of the metal e.g aluminium ore is called bauxite (it is aluminium oxide)

Question 3

how can the economics (profitability) change over time?

Answer 3

if the market price of a metal drops a lot, it might not be worth extracting it. if the price increases it might be worth extracting it. as technology improves, it becomes possible to extract more metal from a sample of rock than was originally possible (i.e worth extracting metal that wasn’t worth extracting in the past)

Question 4

what are the two ways of extracting metals from their ores?

Answer 4

reduction with carbon and electrolysis

Question 5

why do some ores have to be concentrated before the metal is extracted?

Answer 5

to git rid of unwanted rocky metal

Question 6

what can be done to purify extracted metal?

Answer 6

electrolysis

Question 7

what happens when an ore is reduced?

Answer 7

oxygen is removed from it

Question 8

which metals can be extracted by reduction using carbon?

Answer 8

metals below carbon in the reactivity series, because carbon can only take the oxygen away from metals less reactive than carbon itself

Question 9

which metals can be extracted be electrolysis?

Answer 9

metals higher than carbon in the reactivity series (expensive to do)

Question 10

why is electrolysis used to purify copper?

Answer 10

copper extracted by reduction is impure so doesn’t conduct electricity well- not useful. electrolysis produces pure copper which is a much better conductor

Question 11

what is electrolysis?

Answer 11

the breaking down of a substance using electricity

Question 12

what is an electrolyte?

Answer 12

a liquid which conducts the electricity

Question 13

what are electrolytes often made of?

Answer 13

metal salt solutions made from the ore (e.g copper sulfate)

Question 14

why can electrolytes conduct electricity?

Answer 14

they have free ions

Question 15

what happens at the anode?

Answer 15

electrons are taken away

Question 16

what happens at the cathode?

Answer 16

electrons are given away

Question 17

how is electrolysis used to get copper?

Answer 17

electrons are pulled off copper atoms at the anode and they go into the solution as Cu2+ ions. Cu2+ ions near the cathode gain electrons and turn back into copper atoms. Impurities dropped at anode as sludge and pure copper atoms bond to the cathode

Question 18

with the electrolysis of copper, what is the cathode made of?

Answer 18

a thin piece of pure copper (more pure copper adds to it)

Question 19

with the electrolysis of copper, what is the anode made of?

Answer 19

impure copper which will dissolve

Question 20

what will happen if you put a reactive metal into a solution of a dissolved metal compound?

Answer 20

the reactive metal will replace the less reactive metal in the compound

Question 21

why do more reactive metals displace less reactive metals?

Answer 21

the more reactive metal bonds more strongly to the non metal bit of the compound and pushes out the less reactive metal

Question 22

what happens if you put a piece of silver metal into a solution of copper sulfate

Answer 22

nothing, the more reactive metal (copper) is already in the solution

Question 23

what is bio leaching?

Answer 23

using bacteria to separate copper from copper sulfide. bacteria get energy from bond between copper and sulfur, separating out the copper from the ore in the process. the leachate (solution produced) contains copper which can be extracted eg by filtering

Question 24

what is phytomining?

Answer 24

growing plants in soil containing copper, the plants can’t use or get rid of the copper so it gradually builds up in the leaves. Plants can be harvested, dried and burned in a furnace. The copper can be collected from the ash left in furnace

Question 25

advantage and disadvantage of new methods of copper mining

Answer 25

smaller impact than traditional methods, but they are slow

Question 26

advantages of mining metal ores

Answer 26

1. useful products made
2. jobs provided and brings money into the area
3. so services such as health and transport can be improved

Question 27

disadvantages of mining metal ores

Answer 27

1. bad for the environment
2. noisy
3. scars landscape
4. loss of habitat
5. deep mine shafts dangerous for long time after mine has been abandoned

Question 28

why should metals be recycled?

Answer 28

1. mining and extracting takes lots of energy from fossil fuels, so recycling conserves fossil fuels which are running out. Also, burning them contributes to acid rain, global dimming and climate change
2. recycling metals uses a small fraction of energy needed to mine and extract new metal
3. recycling saves money-energy not cheap
4. finite about of metal on earth-recycling conserves resources
5. recycling cuts down on amount of rubbish sent to landfill, landfill takes up space and pollutes surroundings