Electrochemistry Lesson 1 Introduction. Electrochemistry Is the study of reactions that gain or lose electrons.

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