C6.1 Extracting metals

Question 1

What is an ore?

Answer 1

Metal compound which is mined then the metal is extracted

Question 2

What is below hydrogen in the reactivity series, in order?

Answer 2

Copper
Silver
Gold
Platinum

Question 3

What is the copper carbonate ore?

Answer 3

Malachite

Question 4

What is the aluminium oxide ore?

Answer 4

Bauxite

Question 5

What is the iron oxide ore?

Answer 5

Haematite

Question 6

Method for extracting aluminium?

Answer 6

Electrolysis

Question 7

Why is electrolysis expensive?

Answer 7

Energy/ electricity for the current ( anode , cathode) and energy to melt ore so it is molten / in solution

Question 8

How can Iron be extracted?

Answer 8

Reduction - adding carbon to displace the metal from its oxide

Question 9

Explain step by step of iron extraction?

Answer 9

Hot air (oxygen) reacts with the coke (carbon) to produce carbon dioxide
More coke is added to the furnace and reduces the carbon dioxide into carbon monoxide.
iron(III) oxide is reduced.

Question 10

Once molten iron is formed, what does it contain which needs to be removed

Answer 10

Sandy impurities

Question 11

How are sandy impurities removed?

Answer 11

using limestone (calcium carbonate) which reacts with silica (sand) to form slag, a molten mixture that floats on top of the molten iron and can be tapped off

Question 12

What is calcium silicate called?

Answer 12

slag

Question 13

Why do metals have high melting points?

Answer 13

Strong metallic bonds

Question 14

Why is cryolite used to melt aluminium?

Answer 14

It would be very expensive otherwise

Question 15

How does cryolite work with aluminium?

Answer 15

Aluminium oxide is dissolved in cryolite. Cryolite has a lower melting point so uses less energy

Question 16

in electrolysis

Where does aluminium go?

Answer 16

To the cathode, around the edge

Question 17

in electrolysis

Where does the oxygen go?

Answer 17

Anode, to the top bits

Question 18

What does the oxygen react with at the anode?

Answer 18

Carbon to form carbon dioxide

Question 19

What is cryolite?

Answer 19

A aluminium compound

Question 20

Why does aluminium oxide need to be molten?

Answer 20

So the ions become charged and move

Question 21

for oxygen

What is the half equation at the anode?

Answer 21

2O^2- = O2 + 4e-

Question 22

What is the half equation at the cathode?

Answer 22

Al3+ + 3e- = Al

Question 23

Why does the anode need to be replaced regularly?

Answer 23

It is made out of carbon (graphite) and reacts with the oxygen

Question 24

What is electrolysis?

Answer 24

the breakdown of compounds into ions using electricity

Question 25

Where are most metals found?

Answer 25

In the earths crust, already reacted with with elements like oxygen

Question 26

What does economical mean?

Answer 26

Cost effective

Question 27

What is a low grade ore?

Answer 27

Contain only a small amount of a metal

Question 28

Is it harder or easier to extract copper economically from low grade ores?

Answer 28

Harder

Question 29

Explain bioleaching?

Answer 29

Bacteria is mixed with a low grade ore. The bacteria can break down low grade ore to produce acidic solution containing copper ions also known as a leachate.

Question 30

What is Leachate?

Answer 30

The extracted metal we want

Question 31

Positives (3) of bioleaching?

Answer 31

POS- doesnt produce any harmful gases, doesnt damage landscape, works at a lower temperature so less energy is needed = cheaper

Question 32

Negatives (4) of bioleaching?

Answer 32

NEG - Slow process , toxic chemicals are released, low efficiency for bacteria to convert copper ore into copper metal. A lot of waste is produces

Question 33

Why are phytoextraction and bioleaching good economically and sustainably?

Answer 33

Both allow economically extraction of metals from low grade ores. This is important as there is a limited supply of earths resources

Question 34

After bioleaching and phytoextraction, what do you have?

Answer 34

A metal compound

Question 35

What do you need to do after bioleaching and phytoextraction?

Answer 35

Process the metal compound. Iron is more reactive than copper so scrap iron is also cheaper than copper so can displace the copper from the Leachate. Cost effective way to produce copper from leachate OR the leachate can be electrolysed

Question 36

Positives of Phytoextraction? 3

Answer 36

POS- doesnt produce any harmful gases, doesnt damage landscape, Plants photosynthesise so better for the environment

Question 37

Negatives of phytoextraction?

Answer 37

Very slow as plant needs to grow, crops may need replanting and maintenance

Question 38

Explain phytoextraction?

Answer 38

Growing plants that contain metal compounds within them. Metal build up in leaves, when burned in a furnace it turns into ashes. And then you can separate the metals found in the acid by displacement or electrolysis