Extracting Pure Copper

Question 0

What does electrolysis do?

Answer 0

Splits up pure copper from impurities using electricity

Question 1

Where does copper come from?

Answer 1

Dug from ground as copper ore
Mixed with carbon and heated
Then needs to be made pure with electrolysis

Question 2

How does electrolysis work?

Answer 2

Copper immersed in electrolyte which conducts electricity
Electrolytes are free ions dissolved in water
Electrical supply acts as electron pump
Pulls electrons off copper atoms at the anode
They go into solution as Cu2+ ions
It offers electrons at the cathode, turns them back to copper atoms
Impurities are dropped at anode as sludge

Question 3

Are cathode and anode positive or negative?

Answer 3

Anode +

Cathode -

Question 4

What reaction takes place at cathode?

Answer 4

Cu2+ (aq) + 2e- = Cu (s)

Reduction - gain of electrons

Question 5

What is the reaction at the anode?

Answer 5

Cu (s) = Cu2 (aq) + 2e-

Oxidation - loss of electrons

Question 6

How does the mass of the anode and cathode change during electrolysis?

Answer 6

Anode loses mass

Cathode gains mass - after weeks can be 20x bigger

Question 7

Why recycle copper?

Answer 7

Cheaper to recycle copper than mine and extract it from ore
Recycling uses 15% of energy needed for extraction
Hard to convince people to recycle - sorting takes time and money