Purifying MetalsPurifying Metals
Aims:
• Describe the purification of copper by electrolysis
• Draw a simple diagram to the show the method used to purify copper
IMPURE COPPER ANODE
PURE COPPER CATHODECopper sulphate
CuSO4 solution
PURIFYING COPPER
Cu2+
Cu
CuCu2+
Cu2+Copper atoms from impure copper are OXIDISED to copper ions
Copper ions transported from anode to cathode
Copper ions from impure copper are REDUCED to copper atoms
As the atoms of the impurities are not transported, the copper that builds up on the cathode is extremely pure.
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?
Cl-
Cl-
Cl-
Cl- Na+ Na+
Na+ Na+
OILRIG
- 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’
Oxidation is loss, reduction is gain
‘OILRIG’
Purification: The half reactions
Anode (+ve electrode)
Cu(s) Cu2+(aq) + 2e-
Cathode (-ve electrode)
Cu2+(aq) + 2e- Cu(s)
Oxidation Is Loss of electrons, Reduction Is Gain (OILRIG)
• 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
Unscramble the words to end the sentences