Date:
Name:
Skill Builder
Class:
The Oxidation Number Method for
Balancing Equations
Chapter 10
BLM 10-3
Goal
Review the oxidation number method for balancing redox reactions and practise
using this method.
The Oxidation
Number Method
Write unbalanced net ionic equation
Assign oxidation numbers to
identify redox reaction
Identify element oxidized and
element reduced
Find increase and decrease in
oxidation numbers
Find smallest whole-number ratio
of oxidized and reduced elements
Acidic Conditions
Include HzO and H+, as
necessary
Basic Conditions
Balance atoms of oxidized and
•: reduced elements
!feNeutral
Conditions
Balance assuming
acidic conditions
Add OH to "neutralize"
H+ions present
Balance other
elements by inspection
Simplify resulting
equation, if possible
Procedure
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On a separate sheet of paper, balance the following equations using the oxidation
number method. Assume neutral conditions. Refer to the above concept organizer for
the steps of the oxidation number method.
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1. Nal + HC1O -> NaIO3 + HC1
2. I2 + HNO3 -> HIO3 + NO2 + H2O
3. C3H8O + CrO3 + H2SO4 -» Cr2(SO4)3 + C3H6O + H2O
4. KC1 + MnO2 + H2SO4 -» K2SO4+ MnSO4 + Fe2 (SO4)3 + H2O
5. Cu + H2SO4-> CuSO4 + H2O + SO2
6. Zn + H2SO4 -> ZnSO4 + H2S + H2O
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Copyright © 2002 McGraw-Hill Ryerson Limited