gcsescience.com 4 gcsescience.com
Extraction of Metals
Electrolysis of Sodium Chloride.
This page shows the electrolysis of pure sodium
You get different products
if the sodium chloride is dissolved in water.
chloride must be
heated until it is molten
before it will conduct electricity. Electrolysis
separates the molten ionic compound into its elements.
What is a Half Equation?
The reactions at each electrode are called half
The half equations are written so that the
same number of electrons occur in each equation.
2Na+ + 2e-
metal at the (-)cathode).
2Cl- - 2e- Cl2 (chlorine gas at the (+)anode).
electrons (reduction) to form
Chloride ions lose electrons (oxidation) to form chlorine atoms.
The chlorine atoms combine to form molecules of chlorine gas.
The overall reaction is
2Na+Cl-(l) 2Na(s) + Cl2(g)
Sodium can be used
in street lamps
and as a coolant in some
nuclear reactors. See some other examples of electrolysis.
Links Electrolysis Revision Questions
gcsescience.com The Periodic Table Index Metal Quiz gcsescience.com
Home GCSE Chemistry GCSE Physics
Copyright © 2015 gcsescience.com. All Rights Reserved.