Transcript Writing Redox Half

Writing Redox
Half-Reactions
Writing Redox HalfReactions
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1. Assign oxidation numbers to each
element in the reaction.
+2 -1
0
+1 -1
0
 CuCl2 + Ag  AgCl + Cu
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2. Identify which element is being
oxidized and which is being reduced.

+2
0
+1
0
CuCl2 + Ag  AgCl + Cu
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Oxidized – Ag (loses 1 electron)
Reduced – Cu2+ (gains 2 electrons)
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3. Write an equation for the oxidation of
one compound and the reduction of the
other.
Include the number of electrons lost or
gained.
Reduction Reaction
Cu+2 + 2e-  Cu
Oxidation Reaction
Ag  Ag+ + e-
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4. Make sure the number of electrons for
both reactions match up. If not, multiply
by the least common multiple so that
they do.
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Reduction Rxn  Cu+2 + 2e-  Cu
Oxidation Rxn  2 (Ag  Ag+ + e-)
Net Rxn 2Ag + Cu2+  2Ag+ + Cu
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