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 Electrolysis of Zinc Chloride

The half equations are

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

back       Links       Electrolysis       Search       Questions       next

gcsescience.com  Contents   The Periodic Table   Index   Quizzes  gcsescience.com

Copyright © 2012 Dr. Colin France. All Rights Reserved.