Electrochemistry is the study of chemical reactions that produce electrical effects

General Information

bull Charge ndash property of matter

bull There are two kinds of chargendash electron rarr -160 x 10-19 C

ndash proton rarr +160 x 10-19 C

bull 10 Coulomb of charge is equivalent to 625 x 1018 electrons

General Information

bull Currentndashflow of charge

ndashmeasured in amperes (A)

bull 1 Ampndashflow of 10 C of charge per second

past a given point (Cs)

General Information

bull Circuitndasha closed pathway for charge to

travel

ndashmay be a solid or fluid path

Conductors in which only electrons can move

Solution of positive and negative ions that are free to move

Voltaic Cell

bull harnessed chemical reaction which produces an electric current

bull converts chemical potential energy into electrical potential energy

Voltaic Cell

Voltaic Cell

bull Salt bridge (U-tube)ndash connects the two half cellsndash allows ions to be exchanged but prevents

mixing of the solutions

bull This reaction is spontaneousndash oxidation (RA) rarr Zn(s) harr Zn+2

(aq) + 2e-

ndash reduction (OA) rarr Cu2+(aq) + 2e- harr Cu(s)

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

General Information

bull Charge ndash property of matter

bull There are two kinds of chargendash electron rarr -160 x 10-19 C

ndash proton rarr +160 x 10-19 C

bull 10 Coulomb of charge is equivalent to 625 x 1018 electrons

General Information

bull Currentndashflow of charge

ndashmeasured in amperes (A)

bull 1 Ampndashflow of 10 C of charge per second

past a given point (Cs)

General Information

bull Circuitndasha closed pathway for charge to

travel

ndashmay be a solid or fluid path

Conductors in which only electrons can move

Solution of positive and negative ions that are free to move

Voltaic Cell

bull harnessed chemical reaction which produces an electric current

bull converts chemical potential energy into electrical potential energy

Voltaic Cell

Voltaic Cell

bull Salt bridge (U-tube)ndash connects the two half cellsndash allows ions to be exchanged but prevents

mixing of the solutions

bull This reaction is spontaneousndash oxidation (RA) rarr Zn(s) harr Zn+2

(aq) + 2e-

ndash reduction (OA) rarr Cu2+(aq) + 2e- harr Cu(s)

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

General Information

bull Currentndashflow of charge

ndashmeasured in amperes (A)

bull 1 Ampndashflow of 10 C of charge per second

past a given point (Cs)

General Information

bull Circuitndasha closed pathway for charge to

travel

ndashmay be a solid or fluid path

Conductors in which only electrons can move

Solution of positive and negative ions that are free to move

Voltaic Cell

bull harnessed chemical reaction which produces an electric current

bull converts chemical potential energy into electrical potential energy

Voltaic Cell

Voltaic Cell

bull Salt bridge (U-tube)ndash connects the two half cellsndash allows ions to be exchanged but prevents

mixing of the solutions

bull This reaction is spontaneousndash oxidation (RA) rarr Zn(s) harr Zn+2

(aq) + 2e-

ndash reduction (OA) rarr Cu2+(aq) + 2e- harr Cu(s)

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

General Information

bull Circuitndasha closed pathway for charge to

travel

ndashmay be a solid or fluid path

Conductors in which only electrons can move

Solution of positive and negative ions that are free to move

Voltaic Cell

bull harnessed chemical reaction which produces an electric current

bull converts chemical potential energy into electrical potential energy

Voltaic Cell

Voltaic Cell

bull Salt bridge (U-tube)ndash connects the two half cellsndash allows ions to be exchanged but prevents

mixing of the solutions

bull This reaction is spontaneousndash oxidation (RA) rarr Zn(s) harr Zn+2

(aq) + 2e-

ndash reduction (OA) rarr Cu2+(aq) + 2e- harr Cu(s)

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

Voltaic Cell

bull harnessed chemical reaction which produces an electric current

bull converts chemical potential energy into electrical potential energy

Voltaic Cell

Voltaic Cell

bull Salt bridge (U-tube)ndash connects the two half cellsndash allows ions to be exchanged but prevents

mixing of the solutions

bull This reaction is spontaneousndash oxidation (RA) rarr Zn(s) harr Zn+2

(aq) + 2e-

ndash reduction (OA) rarr Cu2+(aq) + 2e- harr Cu(s)

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

Voltaic Cell

Voltaic Cell

bull Salt bridge (U-tube)ndash connects the two half cellsndash allows ions to be exchanged but prevents

mixing of the solutions

bull This reaction is spontaneousndash oxidation (RA) rarr Zn(s) harr Zn+2

(aq) + 2e-

ndash reduction (OA) rarr Cu2+(aq) + 2e- harr Cu(s)

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

Voltaic Cell

bull Salt bridge (U-tube)ndash connects the two half cellsndash allows ions to be exchanged but prevents

mixing of the solutions

bull This reaction is spontaneousndash oxidation (RA) rarr Zn(s) harr Zn+2

(aq) + 2e-

ndash reduction (OA) rarr Cu2+(aq) + 2e- harr Cu(s)

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

Voltaic Cell

bull The two metal rods are called electrodes this is where the electrons enter and leave the cellndash The electrode where oxidation occurs is

called the anodendash The electrode where reduction occurs is

called the cathode

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

Voltaic Cell

bull Anodendash electrons leave the cell from the anodendash positive ions are produced

ndash Zn(s) rarr Zn2+(aq) + 2e-

bull Cathodendash electrons enter the cathodendash solid metal is produced

ndash Cu2+(aq) + 2e- rarr Cu(s)

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

Voltaic Cell

anode cathode

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

Voltaic Cell

bull At any time in a given half cell electrical neutrality is maintained by the movement of ions across the salt bridge

bull Negative ions (anions) drift toward the anode

bull Positive ions (cations) drift toward the cathode

The ZnCu Voltaic Cell

The ZnCu Voltaic Cell

Problem

bull Draw a diagram of a copperaluminum voltaic cell Label the anode and cathode and show the direction of electron flow Write the equations for the reactions that occur and predict the cell voltage

Solution

bull Locate the reactions in data bookndash Cu2+

(aq) + 2e- rarr Cu(s) +034

ndash Al3+(aq) + 3e- rarr Al(s) -166

bull For a voltaic cell reverse the lower reaction ( Al is lower on table ndashoxidized)ndash Cu2+

(aq) + 2e- rarr Cu(s) +034

ndash Al(s) rarr Al3+(aq) + 3e- +166

+200

Net ionic reactionCu2+ (aq) + 2e- lt - gt Cu (s)

Al(s) lt - gt Al3+(aq) + 3e-

3 X

2 X

Remember in all redox equations the electrons are removed

3 Cu2+ + 6e- lt - gt 3 Cu(s)

2 Al(s) lt - gt 2Al3+(aq) + 6e-

3 Cu2+ + 2 Al(s) lt - gt 3 Cu(s) + 2Al3+(aq)

ADD

copper aluminum

Cu2+ Al3+

200 V

Voltaic Cellbull the shorthand representation of an

electrochemical cell showing the two half-cells connected by a salt bridge or porous barrier such as

Zn(s)ZnSO4(aq)CuSO4(aq)Cu(s)

anode cathode

Phase boundary

Liquid junction

Remember

bull Redox reactions can be viewed as a competition for electrons Therefore the reaction is always between the strongest oxidizing agent and the strongest reducing agent

Problem

bull A strip of metal X is placed in XNO3 solution It makes an electrochemical cell with Al3+

(aq) half cell It is observed that Al(s) is deposited on the aluminum electrode and the cell voltage is 075 V Calculate the reduction potential of X

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Solution

bull Locate the reactions in data bookndash Cu2+

(aq) + 2e- rarr Cu(s) +034

ndash Al3+(aq) + 3e- rarr Al(s) -166

bull For a voltaic cell reverse the lower reaction ( Al is lower on table ndashoxidized)ndash Cu2+

(aq) + 2e- rarr Cu(s) +034

ndash Al(s) rarr Al3+(aq) + 3e- +166

+200

Net ionic reactionCu2+ (aq) + 2e- lt - gt Cu (s)

Al(s) lt - gt Al3+(aq) + 3e-

3 X

2 X

Remember in all redox equations the electrons are removed

3 Cu2+ + 6e- lt - gt 3 Cu(s)

2 Al(s) lt - gt 2Al3+(aq) + 6e-

3 Cu2+ + 2 Al(s) lt - gt 3 Cu(s) + 2Al3+(aq)

ADD

copper aluminum

Cu2+ Al3+

200 V

Voltaic Cellbull the shorthand representation of an

electrochemical cell showing the two half-cells connected by a salt bridge or porous barrier such as

Zn(s)ZnSO4(aq)CuSO4(aq)Cu(s)

anode cathode

Phase boundary

Liquid junction

Remember

bull Redox reactions can be viewed as a competition for electrons Therefore the reaction is always between the strongest oxidizing agent and the strongest reducing agent

Problem

bull A strip of metal X is placed in XNO3 solution It makes an electrochemical cell with Al3+

(aq) half cell It is observed that Al(s) is deposited on the aluminum electrode and the cell voltage is 075 V Calculate the reduction potential of X

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Net ionic reactionCu2+ (aq) + 2e- lt - gt Cu (s)

Al(s) lt - gt Al3+(aq) + 3e-

3 X

2 X

Remember in all redox equations the electrons are removed

3 Cu2+ + 6e- lt - gt 3 Cu(s)

2 Al(s) lt - gt 2Al3+(aq) + 6e-

3 Cu2+ + 2 Al(s) lt - gt 3 Cu(s) + 2Al3+(aq)

ADD

copper aluminum

Cu2+ Al3+

200 V

Voltaic Cellbull the shorthand representation of an

electrochemical cell showing the two half-cells connected by a salt bridge or porous barrier such as

Zn(s)ZnSO4(aq)CuSO4(aq)Cu(s)

anode cathode

Phase boundary

Liquid junction

Remember

bull Redox reactions can be viewed as a competition for electrons Therefore the reaction is always between the strongest oxidizing agent and the strongest reducing agent

Problem

bull A strip of metal X is placed in XNO3 solution It makes an electrochemical cell with Al3+

(aq) half cell It is observed that Al(s) is deposited on the aluminum electrode and the cell voltage is 075 V Calculate the reduction potential of X

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

copper aluminum

Cu2+ Al3+

200 V

Voltaic Cellbull the shorthand representation of an

electrochemical cell showing the two half-cells connected by a salt bridge or porous barrier such as

Zn(s)ZnSO4(aq)CuSO4(aq)Cu(s)

anode cathode

Phase boundary

Liquid junction

Remember

bull Redox reactions can be viewed as a competition for electrons Therefore the reaction is always between the strongest oxidizing agent and the strongest reducing agent

Problem

bull A strip of metal X is placed in XNO3 solution It makes an electrochemical cell with Al3+

(aq) half cell It is observed that Al(s) is deposited on the aluminum electrode and the cell voltage is 075 V Calculate the reduction potential of X

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Voltaic Cellbull the shorthand representation of an

electrochemical cell showing the two half-cells connected by a salt bridge or porous barrier such as

Zn(s)ZnSO4(aq)CuSO4(aq)Cu(s)

anode cathode

Phase boundary

Liquid junction

Remember

bull Redox reactions can be viewed as a competition for electrons Therefore the reaction is always between the strongest oxidizing agent and the strongest reducing agent

Problem

bull A strip of metal X is placed in XNO3 solution It makes an electrochemical cell with Al3+

(aq) half cell It is observed that Al(s) is deposited on the aluminum electrode and the cell voltage is 075 V Calculate the reduction potential of X

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Remember

bull Redox reactions can be viewed as a competition for electrons Therefore the reaction is always between the strongest oxidizing agent and the strongest reducing agent

Problem

bull A strip of metal X is placed in XNO3 solution It makes an electrochemical cell with Al3+

(aq) half cell It is observed that Al(s) is deposited on the aluminum electrode and the cell voltage is 075 V Calculate the reduction potential of X

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Problem

bull A strip of metal X is placed in XNO3 solution It makes an electrochemical cell with Al3+

(aq) half cell It is observed that Al(s) is deposited on the aluminum electrode and the cell voltage is 075 V Calculate the reduction potential of X

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Solution

bull Al is reduced Al3+(aq) + 3e- rarr Al(s) -166

bull X is oxidized X(s) rarr X+(aq) + e-

bull Solve for -166 + = +075

= 241 VX is being oxidized reduction potential is ndash 241 V

( ) x 3

Al3+(aq) + 3X(s) rarr Al(s) + 3X+

(aq) 075

WS 15-2

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Standard Electrode Potentials

bull A measure of the relative tendency of substances to gain electrons

bull The standard was chosen to be the hydrogen half cell

bull The hydrogen half cell was chosen to be zero This does not mean H+ will not gain electrons

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Hydrogen Electrode

bull consists of a platinum electrode covered with a fine powder of platinum around which H2(g) is bubbled Its potential is defined as zero volts

Hydrogen Half-Cell

H2(g) rarr 2 H+(aq) + 2 e-

reversible reaction

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Hydrogen Electrode

Non reactive

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Standard Electrode Potentials

bull Since the hydrogen half cell has a relative value of 000 V any half cell connected to it will have its standard potential read off of the voltmeter that connects the two half cells

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

A Voltaic Cell With Zinc and the Standard Hydrogen Electrode

[Zn2+]= [H+] = 1000 M

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Standard Electrode Potentials

bull Any half cell that gives up electrons to H+ will have a negative potential since it has less potential to gain electrons than H+

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Standard Electrode Potentials

bull Any half cell that takes electrons from H2(g)

has a positive potential since it has a greater potential to gain electrons than H+

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Standard Electrode Potentials

bull ExamplesndashCuCu2+ rarr Eo = 034 V 034 V

greater potential than H+H2

ndashAlAl3+ rarr Eo = -166 166 V less potential than H+H2

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

If the reduction of mercury (I) in a voltaic cell is desired the half reaction is

Which of the following reactions could be used as the anode (oxidation)

WS 15-22

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Multiple cells

bull If the cells are connected to the anode then add the potentials

bull If the cells are connected at the cathode then subtract the potentials

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Electrolytic cells

bull Electrical energy is converted to chemical energy

bull Non-spontaneous reactions

bull Reaction is still between the strongest OA and RA (OA is not strong enough)

bull Require outside energy source

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Electrolytic cells

bull The Eo value for an electrolytic cell is negative

bull The Eo value is the minimum voltage that must be applied to the cell to force it to react

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

Electrolytic cells

bull In diagramsndashcell with ammeter rarr voltaic

ndashcell with battery rarr electrolytic

anode (+)cathode (-)

ElectroplatingElectrolysis

Electroplating is the process of

ElectroplatingElectrolysis

Electroplating is the process of

ElectroplatingElectrolysis

1) Current = rate of flow of charge

2) I = q t

3) 1 e- = 16 x 10-19 C

4) 1 mol e- = 602 x 1023 e- x 16 x 10-19 C

= 965 x 104 C

current (A) charge (C)

time (s)

Q = 965 x 104 Cmol (Faradayrsquos constant)

ElectroplatingElectrolysis

5) To calculate number of mol of electrons

ne = q Q

ne = q Q

ne = 18000 C 965 x 104 Cmol

ne = 01865 mol of e-

250 A of current runs for 20 hours through a silver nitrate solution Find the mass of silver produced

q = Itq = (250 A) x (7200 s)q = 18 000 C

Ag+(aq) + 1e- rarr Ag(s)

01865mol 01865 mol

m = n x M

m = 01865 mol x 10787 gmol

m = 20 g

Short cut

m = I t M

m = (250 A) (7200 s) (10787 gmol) (965 x 104 Cmol) (1)

m = 20 g

Q V

I rarr current (Amps)

t rarr time (s)

M rarr molar mass (gmol)

Q rarr molar charge (Cmol)

V rarr voltage

m = I t M

100 g = (150 A) t (10787 gmol) (965 x 104 Cmol) (100)

t = 59639589 s = 166 h

Q V

WS 15-33

A person wants to plate an ornament with 100 g of silver The ornament is placed in a salt of silver and a 15 A current is placed through the solution The voltage is 100 How long will the plating process take

Copper plating a key

- +

power

e-

inert anodecathode

Cu2+

NO3-

Molten or Aqueous

Aqueous

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(aq)

ndash Cl- (aq)

ndash H2O(l)

Molten

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(l)

ndash Cl- (l)

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

ElectroplatingElectrolysis

5) To calculate number of mol of electrons

ne = q Q

ne = q Q

ne = 18000 C 965 x 104 Cmol

ne = 01865 mol of e-

250 A of current runs for 20 hours through a silver nitrate solution Find the mass of silver produced

q = Itq = (250 A) x (7200 s)q = 18 000 C

Ag+(aq) + 1e- rarr Ag(s)

01865mol 01865 mol

m = n x M

m = 01865 mol x 10787 gmol

m = 20 g

Short cut

m = I t M

m = (250 A) (7200 s) (10787 gmol) (965 x 104 Cmol) (1)

m = 20 g

Q V

I rarr current (Amps)

t rarr time (s)

M rarr molar mass (gmol)

Q rarr molar charge (Cmol)

V rarr voltage

m = I t M

100 g = (150 A) t (10787 gmol) (965 x 104 Cmol) (100)

t = 59639589 s = 166 h

Q V

WS 15-33

A person wants to plate an ornament with 100 g of silver The ornament is placed in a salt of silver and a 15 A current is placed through the solution The voltage is 100 How long will the plating process take

Copper plating a key

- +

power

e-

inert anodecathode

Cu2+

NO3-

Molten or Aqueous

Aqueous

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(aq)

ndash Cl- (aq)

ndash H2O(l)

Molten

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(l)

ndash Cl- (l)

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

ne = q Q

ne = 18000 C 965 x 104 Cmol

ne = 01865 mol of e-

250 A of current runs for 20 hours through a silver nitrate solution Find the mass of silver produced

q = Itq = (250 A) x (7200 s)q = 18 000 C

Ag+(aq) + 1e- rarr Ag(s)

01865mol 01865 mol

m = n x M

m = 01865 mol x 10787 gmol

m = 20 g

Short cut

m = I t M

m = (250 A) (7200 s) (10787 gmol) (965 x 104 Cmol) (1)

m = 20 g

Q V

I rarr current (Amps)

t rarr time (s)

M rarr molar mass (gmol)

Q rarr molar charge (Cmol)

V rarr voltage

m = I t M

100 g = (150 A) t (10787 gmol) (965 x 104 Cmol) (100)

t = 59639589 s = 166 h

Q V

WS 15-33

A person wants to plate an ornament with 100 g of silver The ornament is placed in a salt of silver and a 15 A current is placed through the solution The voltage is 100 How long will the plating process take

Copper plating a key

- +

power

e-

inert anodecathode

Cu2+

NO3-

Molten or Aqueous

Aqueous

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(aq)

ndash Cl- (aq)

ndash H2O(l)

Molten

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(l)

ndash Cl- (l)

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Short cut

m = I t M

m = (250 A) (7200 s) (10787 gmol) (965 x 104 Cmol) (1)

m = 20 g

Q V

I rarr current (Amps)

t rarr time (s)

M rarr molar mass (gmol)

Q rarr molar charge (Cmol)

V rarr voltage

m = I t M

100 g = (150 A) t (10787 gmol) (965 x 104 Cmol) (100)

t = 59639589 s = 166 h

Q V

WS 15-33

A person wants to plate an ornament with 100 g of silver The ornament is placed in a salt of silver and a 15 A current is placed through the solution The voltage is 100 How long will the plating process take

Copper plating a key

- +

power

e-

inert anodecathode

Cu2+

NO3-

Molten or Aqueous

Aqueous

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(aq)

ndash Cl- (aq)

ndash H2O(l)

Molten

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(l)

ndash Cl- (l)

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

m = I t M

100 g = (150 A) t (10787 gmol) (965 x 104 Cmol) (100)

t = 59639589 s = 166 h

Q V

WS 15-33

A person wants to plate an ornament with 100 g of silver The ornament is placed in a salt of silver and a 15 A current is placed through the solution The voltage is 100 How long will the plating process take

Copper plating a key

- +

power

e-

inert anodecathode

Cu2+

NO3-

Molten or Aqueous

Aqueous

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(aq)

ndash Cl- (aq)

ndash H2O(l)

Molten

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(l)

ndash Cl- (l)

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Copper plating a key

- +

power

e-

inert anodecathode

Cu2+

NO3-

Molten or Aqueous

Aqueous

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(aq)

ndash Cl- (aq)

ndash H2O(l)

Molten

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(l)

ndash Cl- (l)

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Molten or Aqueous

Aqueous

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(aq)

ndash Cl- (aq)

ndash H2O(l)

Molten

bull NaCl rarr Na+ + Cl-

bull Species present

ndash Na+(l)

ndash Cl- (l)

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

bull Calculate the net potentials and write the reactions that occur whenndash NaI(s) is electrolyzed

ndash A solution of NaI(aq) is electrolyzed

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

NaI(s) is electrolyzed

Na+(l) I-

(l)

Na+(l) + e- rarr Na(s) -271

2I-(l) rarr I2(s) + 2e- -054

2Na+(l) + 2I-

(l) rarr 2Na(s) + I2(s) -325

OA RA

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

A solution of NaI(aq) is electrolyzed

H2O(l) Na+(aq) I-

(aq)

2H2O(l) + 2e- rarr H2(g)+ 2OH-(aq) -083

2I-(aq) rarr I2(s) + 2e- -

054

2H2O(l) + 2I-(aq) rarr H2(g)+ 2OH-

(aq) + I2(s) -137

OA RA

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Electrolysis of Brine

Na+

Cl-

H2O OA

RA

2H2O(l) + 2Cl-(aq) rarr H2(g) + 2OH-(aq) + Cl2(g)

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Note

bull The Cl- ion is a stronger reducing agent than H2O during electrolysis of brine even though the table indicates that it is not

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Electrolysis of molten NaCl

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Changing Concentration

bull A change in concentration around the cathode or anode will change the value of Eo for half cells

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Cu(s) rarr Cu2+(aq) + 2e-

bull An increase in concentration of copper ions will cause a shift to the left making less products

bull Increase in concentration around anode causes a decrease in Eo

Cu(s)

Cu2+

Anode

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Cu2+(aq) + 2e- rarr Cu(s)

bull An increase in concentration of copper ions will cause a shift to the right making more products

bull Increase in concentration around cathode causes a increase in Eo

Cu(s)

Cu2+

Cathode

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

bull Since E(Fe2+Fe) lt E(O2H2O) iron can be oxidized by oxygen

bull Cathodendash O2(g) + 4 H+

(aq) + 4 e- 2 H2O(l)

bull Anode ndash Fe(s) Fe2+

(aq) + 2 e-

bull Fe2+ initially formed ndash further oxidized to Fe3+ which forms rust

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Rusting (Corrosion) of Iron

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Preventing the Corrosion of Iron

bull Corrosion can be prevented by coating the iron with paint or another metal

bull Galvanized iron - Fe is coated with Znbull Zn protects the iron (Zn - anode and Fe -

the cathode)

Zn2+(aq) +2e- Zn(s) E(Zn2+Zn) = -076 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Preventing the Corrosion of Iron

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Preventing the Corrosion of Iron

To protect underground pipelines a sacrificial anode is added

The water pipe - turned into the cathode and an active metal is used as the sacrificial anode

Mg is used as the sacrificial anode

Mg2+(aq) +2e- Mg(s) E(Mg2+Mg) = -237 V

Fe2+(aq) + 2e- Fe(s) E(Fe2+Fe) = -044 V

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Corrosion Prevention

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Living Battery

bull The eel generates electric charge in a battery of biological electrochemical cells each cell providing about 015 V and an overall potential difference of ~ 700 V Note that the eels head is the cathode(+) and its tail the anode(-) The cells extend over the length of the eel

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Types of Batteries

Batteriesndash device that converts chemical energy into electricity

Primary Cellsndash non-reversible electrochemical cellndash non-rechargeable cell

Secondary Cellsndash reversible electrochemical cellndash rechargeable cell

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Types of Batteries

Primary Cells

dry cell amp alkaline cell 15 vcell

mercury cell 134 vcell

fuel cell 123vcell

Secondary Cells

lead-acid (automobile battery) 2 vcell

NiCad 125 vcell

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Lead-Acid Battery

bull A 12 V car battery - 6 cathodeanode pairs each producing 2 V

Cathode PbO2 on a metal grid in sulfuric acid

PbO2(s) + SO42-

(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l)

Anode Pb

Pb(s) + SO42-

(aq) PbSO4(s) + 2e-

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

A Picture of a Car Battery

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

An Alkaline Battery

bull Anode Zn cap

Zn(s) Zn2+(aq) + 2e-

bull Cathode MnO2 NH4Cl and carbon paste

2 NH4+

(aq) + 2 MnO2(s) + 2e- Mn2O3(s) + 2NH3(aq) + 2H2O(l)

bull Graphite rod in the center - inert cathode

bull Alkaline battery NH4Cl is replaced with KOH

bull Anode Zn powder mixed in a gel

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

ldquoDryrdquo Cell

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

The Alkaline Battery

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

ldquoNewrdquo Super Iron Battery

BaFeO4 + 32 Zn rarr 12 Fe2O3 + 12 ZnO + BaZnO2

Environmentally friendlier than MnO2 containing batteries

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

Fuel Cells

bull Direct production of electricity from fuels occurs in a fuel cell

bull H2- O2 fuel cell was the primary source of electricity on Apollo moon flights

bull Cathode reduction of oxygen

2 H2O(l) + O2(g) + 4 e- 4 OH-(aq)

bull Anode

2 H2(g) + 4 OH-(aq) 4 H2O(l) + 4 e-

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71

• Slide 1
• General Information
• Slide 3
• Slide 4
• Voltaic Cell
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• The ZnCu Voltaic Cell
• Problem
• Solution
• Net ionic reaction
• Slide 16
• Slide 17
• Remember
• Slide 19
• Slide 20
• Standard Electrode Potentials
• Hydrogen Electrode
• Slide 23
• Slide 24
• A Voltaic Cell With Zinc and the Standard Hydrogen Electrode
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Multiple cells
• Slide 31
• Electrolytic cells
• Slide 33
• Slide 34
• ElectroplatingElectrolysis
• Slide 36
• Slide 37
• Slide 38
• Short cut
• Slide 40
• Copper plating a key
• Molten or Aqueous
• Slide 43
• NaI(s) is electrolyzed
• A solution of NaI(aq) is electrolyzed
• Electrolysis of Brine
• Note
• Slide 48
• Changing Concentration
• Slide 50
• Slide 51
• Slide 52
• Rusting (Corrosion) of Iron
• Preventing the Corrosion of Iron
• Slide 55
• Slide 56
• Corrosion Prevention
• Slide 58
• Slide 59
• Slide 60
• Living Battery
• Types of Batteries
• Slide 63
• Lead-Acid Battery
• A Picture of a Car Battery
• An Alkaline Battery
• ldquoDryrdquo Cell
• The Alkaline Battery
• ldquoNewrdquo Super Iron Battery
• Fuel Cells
• Slide 71