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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.

Electrolysis of Zinc Chloride

The half equations are

Zn2+  +  2e-    arrow   Zn (zinc metal at the (-)cathode).
Cl-  -  2e-    arrow   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

ZnCl2(l)      arrow     Zn(s)  +   Cl2(g)

See some other examples of electrolysis.

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