Extraction of Metals

Electrolysis of Sodium Chloride.

This page shows the electrolysis of pure sodium chloride.
You get different products if
the s
odium chloride is dissolved in water.

Sodium chloride must be heated until it is molten
before it will conduct electricity.
Electrolysis separates the molten ionic compound into its elements.

Electrolysis of Sodium Chloride

The reactions at each electrode are called half equations.
The half equations are written so that the same number of electrons
occur in each equation.

2Na+  +  2e-    arrow   2Na (sodium metal at the (-)cathode).
2Cl-  -  2e-    arrow   Cl2 (chlorine gas at the (+)anode).

Sodium ions gain electrons (reduction) to form sodium atoms.
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)      arrow     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.

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