S = Redox, Purification of Copper

Question 0

1. Mnemonic for redox reactions?
2. What is oxidation?
3. What is reduction?

Answer 0

1. OIL RIG (electrons)
2. loss of electrons, gain of oxygen
3. gain of electrons, loss of oxygen

Question 1

Half ionic equation that occurs at:

Anode and cathode?

Answer 1

Anode:
Cu(s) - 2e- –> Cu2+(aq)

Cathode:
Cu2+(aq) + 2e- –> Cu(s)

Question 2

Copper purification:

What happens to the mass of the electrodes?

Answer 2

The cathode gains mass and the anode dissolves into the electrolyte leaving behind anode sludge. The anode loses mass.

Question 3

Copper purification:

Use of the anode sludge?

Answer 3

It may contain valuable metals such as gold, platinum… These are extracted from the anode sludge and sold.

Question 4

Name the electrolyte used in copper purification

Answer 4

Commonly: Copper(II) Sulphate