Electrochemistry Lesson 1 Introduction. Electrochemistry Is the study of reactions that gain or lose electrons.
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ElectrochemistryLesson 1
Introduction
Electrochemistry
Is the study of reactions that gain or lose electrons.
Electrochemistry
Is the study of reactions that gain or lose electrons.
In this unit we will study:
Battery Reactions
Corrosion
Preventing Corrosion
Combustion
Electroplating
Refining Metals
Oxidation means loss of electrons
LEO
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Na →
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Na →
metal ion
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Na → Na+
metal ion
Balance charge Add electron to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Na → Na+
metal ion
Balance charge Add electron to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
0 +1
Na → Na+
metal ion
Balance charge Add electron to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
0 0
Na → Na+ + 1e-
metal ion
Balance charge Add electron to most positive side
Oxidation- electrons are on the right
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Al →
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Al →
metal ion
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Al → Al3+
metal ion
Balance charge Add electrons to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
Al → Al3+
metal ion
Balance charge Add electrons to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
0 +3
Al → Al3+
metal ion
Balance charge Add electrons to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
0 0
Al → Al3+ + 3e-
metal ion
Balance charge Add electrons to most positive side
Oxidation- electrons are on the right
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
O2- →
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
O2- →
anion atom
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
O2- → O2
anion atom
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
O2- → O2
anion atom
Balance for numbers
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
2O2- → O2
anion atom
Balance for numbers
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
2O2- → O2
anion atom
Balance for numbers
Balance charge Add electrons to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
-4 0
2O2- → O2
anion atom
Balance for numbers
Balance charge Add electrons to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
-4 -4
2O2- → O2 + 4e-
anion atom
Balance for numbers
Balance charge Add electrons to most positive side
Oxidation means loss of electrons
LEO LossElectronsOxidation
Oxidation Half Reactions
show how Metals or Anions lose electrons
2O2- → O2 + 4e-
anion atom
Balance for numbers
Oxidation- electrons are on the right
Balance charge Add electrons to most positive side
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
Ga3+ →
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
Ga3+ →
cation atom
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
Ga3+ → Ga
cation atom
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
+3 0
Ga3+ → Ga
cation atom Balance charge Add electrons to most positive side
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
0 0
Ga3+ + 3e- → Ga
cation atom Balance charge Add electrons to most positive sideReduction- electrons are on the left
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
N2 →
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
N2 →
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
N2 → N3-
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
N2 → 2N3-
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
N2 + 6e- → 2N3-
Reduction means gain of electrons
GER GainElectronsReduction
Reduction Half Reactions
show how Nonmetals or Cations gain electrons
N2 + 6e- → 2N3-
Reduction- electrons are on the left
Balance each simple half reaction
1. Ca →
2. F2 →
3. O2 →
4. Ga →
5. Br - →
6. Li+ →
Balance each simple half reaction
1. Ca → Ca2+ + 2e-
2. F2 + 2e- → 2F-
3. O2 + 4e- → 2O2-
4. Ga →
5. Br - →
6. Li+ →
Balance each simple half reaction
1. Ca → Ca2+ + 2e-
2. F2 + 2e- → 2F-
3. O2 + 4e- → 2O2-
4. Ga → Ga3+ + 3e-
5. 2Br - → Br2 + 2e-
6. Li+ + e- → Li
Balance each simple half reaction
1. Ca → Ca2+ + 2e- oxidation
2. F2 + 2e- → 2F- reduction
3. O2 + 4e- → 2O2- reduction
4. Ga → Ga3+ + 3e- oxidation
5. 2Br - → Br2 + 2e- oxidation
6. Li+ + e- → Li reduction
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)3
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
Al → Al3+ + 3e- oxidation
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
Al → Al3+ + 3e- oxidation
Zn2+
Use metals/cations
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
Al → Al3+ + 3e- oxidation
Zn2+ + 2e- → Zn reduction
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
2(Al → Al3+ + 3e-) oxidation
3(Zn2++ 2e- → Zn) reduction
Balance electrons
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
2(Al → Al3+ + 3e-) oxidation
3(Zn2++ 2e- → Zn) reduction
2Al + 3Zn2+ + 6e- → 2Al3+ + 3Zn + 6e- redox
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
2(Al → Al3+ + 3e-) oxidation
3(Zn2++ 2e- → Zn) reduction
2Al + 3Zn2+ + 6e- → 2Al3+ + 3Zn + 6e- redox
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
2(Al → Al3+ + 3e-) oxidation
3(Zn2++ 2e- → Zn) reduction
2Al + 3Zn2+ → 2Al3+ + 3Zn redox
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
2(Al → Al3+ + 3e-) oxidation
3(Zn2++ 2e- → Zn) reduction
2Al + 3Zn2+ → 2Al3+ + 3Zn redox
Check charge
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
2(Al → Al3+ + 3e-) oxidation
3(Zn2++ 2e- → Zn) reduction
2Al + 3Zn2+ → 2Al3+ + 3Zn redox
+6 +6
Check charge
Redox Reactions
Both oxidation and reduction must occur.
The number of electrons gained must be equal to the number of electrons lost.
It is simpler to write the net ionic equation.
1. Al + Zn(NO3)2
2(Al → Al3+ + 3e-) oxidation
3(Zn2++ 2e- → Zn) reduction
2Al + 3Zn2+ → 2Al3+ + 3Zn redox
+6 +6
Check charge Same!
2. Cl2 + Na
2. Cl2 + Na
Cl2 + 2e- → 2Cl- reduction
2. Cl2 + Na
Cl2 + 2e- → 2Cl- reduction
Na → Na+ + 1e- oxidation
2. Cl2 + Na
Cl2 + 2e- → 2Cl- reduction
2(Na → Na+ + 1e-) oxidation
2. Cl2 + Na
Cl2 + 2e- → 2Cl- reduction
2(Na → Na+ + 1e-) oxidation
Cl2 + 2Na → 2Cl- + 2Na+ redox
0 0
Oxidizing Agents
Oxidizing Agents cause oxidation by undergoing reduction.
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons.
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+ F2
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+ F2 Na+
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+ F2 Na+
Cl2 + 2e- → 2Cl-
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+ F2 Na+
Cl2 + 2e- → 2Cl-
Ca2+ + 2e- → Ca
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+ F2 Na+
Cl2 + 2e- → 2Cl-
Ca2+ + 2e- → Ca
Both can gain electrons
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+ F2 Na+
Cl2 + 2e- → 2Cl-
Ca2+ + 2e- → Ca
Both can gain electrons
Oxidizing Agents cause oxidation by undergoing reduction.
They gain electrons. Nonmetals and cations are oxidizing agents because they gain electrons.
Cl2 Ca2+ F2 Na+
Cl2 + 2e- → 2Cl-
Ca2+ + 2e- → Ca
Both can gain electrons
Reducing Agents
Reducing Agents cause reduction by undergoing oxidation.
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons.
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3-
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3- Al
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3- Al O2-
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3- Al O2- Li
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3- Al O2- Li
2N3- → N2 + 6e-
Al → Al3+ + 3e-
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3- Al O2- Li
2N3- → N2 + 6e-
Al → Al3+ + 3e-
Both can lose electrons
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3- Al O2- Li
2N3- → N2 + 6e-
Al → Al3+ + 3e-
Both can lose electrons
Reducing Agents cause reduction by undergoing oxidation.
They lose electrons. Metals and anions are reducing agents because they lose electrons.
N3- Al O2- Li
2N3- → N2 + 6e-
Al → Al3+ + 3e-
Both can lose electrons
You need to be able to tell an oxidizing agent from a reducing agent.
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
Ga Rb+ I- P4
Fe Co2+ S I2
Cu Pb2+ Li Br-
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
Ga Rb+ I- P4
Fe Co2+ S I2
Cu Pb2+ Li Br-
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
Ga Rb+ I- P4
Fe Co2+ S I2
Cu Pb2+ Li Br-
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
Ga Rb+ I- P4
Fe Co2+ S I2
Cu Pb2+ Li Br-
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
Ga Rb+ I- P4
Fe Co2+ S I2
Cu Pb2+ Li Br-
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
Ga Rb+ I- P4
Fe Co2+ S I2
Cu Pb2+ Li Br-
You need to be able to tell an oxidizing agent from a reducing agent. Circle each oxidizing agent.
They can reduce or gain electrons
Ga Rb+ I- P4
Fe Co2+ S I2
Cu Pb2+ Li Br-
Label each reactant as an oxidizing or reducing agent.
2Ag+ + Pb → 2Ag + Pb2+
Label each reactant as an oxidizing or reducing agent.
2Ag+ + Pb → 2Ag + Pb2+
Reduction
Label each reactant as an oxidizing or reducing agent.
2Ag+ + Pb → 2Ag + Pb2+
Reduction Oxidation
Label each reactant as an oxidizing or reducing agent.
2Ag+ + Pb → 2Ag + Pb2+
Reduction Oxidation
Ox Agent
Label each reactant as an oxidizing or reducing agent.
2Ag+ + Pb → 2Ag + Pb2+
Reduction Oxidation
Ox Agent Red Agent
Label each reactant as an oxidizing or reducing agent.
6I- + 2Al3+ → 3I2 + Al
Label each reactant as an oxidizing or reducing agent.
6I- + 2Al3+ → 3I2 + Al
Oxidation
Label each reactant as an oxidizing or reducing agent.
6I- + 2Al3+ → 3I2 + Al
Oxidation Reduction
Label each reactant as an oxidizing or reducing agent.
6I- + 2Al3+ → 3I2 + Al
Oxidation Reduction
Red Agent
Label each reactant as an oxidizing or reducing agent.
6I- + 2Al3+ → 3I2 + Al
Oxidation Reduction
Red Agent Ox Agent
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