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Extraction of Metals

Electrolysis of Zinc Chloride.

Zinc can be extracted from zinc oxide by heating with carbon
or from zinc chloride by electrolysis.

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

The half equations are

Zn²⁺  +  2e^-       Zn (zinc metal at the (-)cathode).
2Cl^-  -  2e^-       Cl₂ (chlorine gas at the (+)anode).

Zinc ions gain electrons (reduction) to form zinc atoms.
Chloride ions lose electrons (oxidation) to form chlorine atoms.
The chlorine atoms combine to form molecules of chlorine gas.

The overall reaction is

ZnCl_2(l)           Zn_(s)  +   Cl_2(g)

See some other examples of electrolysis.

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