This document discusses electrolytic cells, which use an electric current to drive non-spontaneous redox reactions called electrolysis. In electrolytic cells, the cathode is the negative electrode where reduction occurs and the anode is the positive electrode where oxidation occurs, unlike in voltaic cells. Electrolytic cells are used for processes like metal extraction and refining, electroplating, and producing industrial gases. They involve immersing inert electrodes in a common electrolyte, with the cathode being the negative terminal of the power supply where positive ions are reduced.

1. IB Chemistry Power Points
Topic 09
Electrolytic Cells SL
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2. Electrolytic Cells
an electric current is used to drive a non-spontaneous redox reaction
This process is called electrolysis

3. Electric current enters and exits the cell by electrodes
Electrolytic cells often use inert electrodes (electrodes that
don’t react).
Like voltaic cells:
1. Cathode: - electrode at which reduction occurs
2. Anode: - electrode at which oxidation occurs
Unlike voltaic cells: cathode is (-) & anode is (+)
Electrodes are immersed in a common electrolyte.

4. Cathode is the
negative terminal of
the power supply
This is the site of
reduction of +ive ions
in electrolyte
Negative ions are
oxidized at the anode.
Electrolytic cells are used for extraction, refining,
electroplating, commercial manufacture of gases, etc.

5. Predicting electrolysis products
Molten Salt Electrolytes
REQUIRES – molten salt and inert electrodes
ALWAYS – metal cation reduced at cathode, nonmetal anion
oxidized at anode.
Write the cathode, anode and overall rxns for this example
Pb2+ (l) + 2e-  Pb (l)
2Br- (l)  Br2 (g) + 2e-
Pb2+ (l) + 2Br- (l)  Pb (l) + Br2 (g)