1. Purifying Metals Aims:
Describe the purification of copper by electrolysis
Draw a simple diagram to the show the method used to purify copper

2. Copper
How do you get copper?
What is it used for?

3. Purifying Copper

4. Copper sulphate CuSO4 solution
PURIFYING COPPER
IMPURE COPPER ANODE
PURE COPPER CATHODE
Copper sulphate CuSO4 solution
Cu2+
Cu2+
Copper atoms from impure copper are OXIDISED to copper ions
Copper ions from impure copper are REDUCED to copper atoms Cu
Cu2+ Cu
Copper ions transported from anode to cathode
As the atoms of the impurities are not transported, the copper that builds up on the cathode is extremely pure.

5. Why will the concentration of the solution stay the same?
IMPURE COPPER ANODE
PURE COPPER CATHODE
IMPURE COPPER ANODE
PURE COPPER CATHODE
Over time, the impure anode dissolves away and the impurities sink to the bottom. The pure cathode grows as more pure copper is deposited on it.
Why will the concentration of the solution stay the same?

6. Oxidation is loss, reduction is gain
OILRIG
Oxidation is loss, reduction is gain
‘OILRIG’
Na+
Na+
Cl-
Cl-
Na+
Na+
Cl-
Cl-
ions LOSING electrons to become atoms is called ‘OXIDATION’
(even though oxygen may not be involved)
+ ions GAINING electrons to become atoms is called ‘REDUCTION’

7. Purification: The half reactions
Oxidation Is Loss of electrons, Reduction Is Gain (OILRIG)
Anode (+ve electrode)
Cu(s)  Cu2+(aq) + 2e-
Cathode (-ve electrode)
Cu2+(aq) + 2e-  Cu(s)

8. Copper is purified to improve its Copper is purified by
Unscramble the words to end the sentences
Copper is purified to improve its
NOT CIVIC DUTY
Copper is purified by
CELERY IS LOST
Pure copper forms at the
DO TEACH
Impurities form called
A ODD MENU
The anode will slowly
DIVE LOSS
At the cathode copper ions gain
CORN STEEL
conductivity
electrolysis
cathode
anode mud
dissolve
electrons