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Extraction of Copper - Purification.

The anode is a block of impure copper.
The cathode is a thin piece of
pure copper.
When electricity is passed through the cell
copper is dissolved at the anode by oxidation, Cu2+ ions go into solution.
Cu(s) - 2e-
Cu2+(aq)
At the cathode, copper is deposited by reduction.
Cu2+(aq) +
2e-
Cu(s)
As copper
ions move from the anode to the
cathode
the anode gets smaller as the cathode gets bigger.
This is a redox
reaction.
The rate at which the copper
ions enter the electrolyte from the anode
is the same as the rate at
which the copper ions
leave the
electrolyte at the cathode. The concentration of
the copper(II) sulfate
solution therefore remains
unchanged (continued).
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