Download Unit 14.1 REDOX Reactions Objectives REDOX Reactions

Unit 14.1 REDOX Reactions
Teacher: Dr. Van Der Sluys
Objectives
• REDOX
– Oxidation
– Reduction
– Oxidizing agent
– Reducing agent
REDOX Reactions
• REDOX reactions involve the transfer of
electrons from one species to another.
• A REDOX reaction involves both an
oxidation of one species and a reduction
of another.
• REDOX reactions can be used to convert
chemical potential energy into electrical
energy.
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Oxidation
• A loss of electrons
• An increase in the oxidation number
• A half-reaction in which the electrons are
products.
Reduction
• A gain of electrons
• A decrease in the oxidation number
• A half-reaction in which electrons are a
reactant.
Identifying the Oxidized and
Reduced Species
• Determine the oxidation number of an element on both
the reactant and product side of the reaction. If the
oxidation number increases, the atom was oxidized.
Cu (s) + 2 AgNO3 (aq) --> Cu(NO3) 2 (aq) + 2 Ag (s)
• Elemental copper has a zero oxidation state as a
reactant, which increases to 2+ in the product Cu(NO3)2,
hence the copper is oxidized.
• The reactant AgNO3 has silver in the +1 oxidation state,
which is reduced to 0 in the product, elemental silver.
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Examples - Net Ionic Equations
• Identify the species that is oxidized and
reduced in the following.
2 Fe3+ (aq) + Zn (s) --> 2 Fe2+ (aq) + Zn2+ (aq)
4 H+ (aq) + MnO4- (aq) + Co2+ (aq) --> MnO2 (s) + Co3+ (aq) + 2 H2 O (l)
2 Cl- (aq) + F2 --> Cl2 (g) + 2 F - (aq)
Examples - Molecular Formulas
2 H2 (g) + O2 (g) --> 2 H2O (l)
2 H2SO4 (aq) + 2 NaBr (aq) -->
Br2 (l) + SO2 (g) + Na2SO4 (aq) + 2 H2O (l)
I2O5 (s) + 5 CO (g) --> I2 (s) + 5 CO5 (g)
Oxidizing and Reducing Agents
• An oxidizing agent is the species that gets
reduced in a REDOX reaction
• A reducing agent is the species that gets
oxidized in a REDOX reaction.
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Examples - Identifying the
Oxidizing and Reduxing Agents
Cr2O7 2- (aq) + 14 H+ (aq) + 6 I- (aq) -->
2 Cr3+ (aq) + 3 I2 (s) + 7 H2O (l)
Zn (s) + 2 H+ (aq) --> Zn2+ (aq) + H2 (g)
16 H+ (aq) + 2 MnO4 - (aq) + 5 C2O4 2- (aq) -->
2 Mn2+ (aq) + 8 H2O (l) + 10 CO2 (g)
Conclusion
• REDOX reactions involve oxidation and
reduction and occur by the transfer of
electrons from the reducing agent to the
oxidizing agent.
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