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Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10 V at 25 o C. (V is the unit for voltage). 1

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Page 1: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

1

Standard Electrode Potentials When the concentrations of Cu2+

(aq) and Zn2+(aq) are

both kept at unit activity, the emf of the galvanic cell is 1.10 V at 25 oC. (V is the unit for voltage).

Page 2: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

2

Standard Electrode Potentials When the concentrations of Cu2+

(aq) and Zn2+(aq) are

both kept at unit activity, the emf of the galvanic cell is 1.10 V at 25 oC. (V is the unit for voltage).

Recall: The activity of a species X can be written as

where is called the activity coefficient.

[X]a XX γ

Xγ

Page 3: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

3

Standard Electrode Potentials When the concentrations of Cu2+

(aq) and Zn2+(aq) are

both kept at unit activity, the emf of the galvanic cell is 1.10 V at 25 oC. (V is the unit for voltage).

Recall: The activity of a species X can be written as

where is called the activity coefficient. For fairly dilute solutions, , so that .

[X]a XX γ

1X γXγ

[X]aX

Page 4: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

4

Standard Electrode Potentials When the concentrations of Cu2+

(aq) and Zn2+(aq) are

both kept at unit activity, the emf of the galvanic cell is 1.10 V at 25 oC. (V is the unit for voltage).

Recall: The activity of a species X can be written as

where is called the activity coefficient. For fairly dilute solutions, , so that . We will make the gross assumption (as does the text) that

at a concentration of 1 M, and replace unit activity for Cu2+

(aq) and Zn2+(aq) by concentrations of 1

M.

[X]a XX γ

1X γXγ

[X]aX

1X γ

Page 5: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

5

The value of the emf is independent of the amount of solution or the size of the electrodes.

Page 6: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

6

The value of the emf is independent of the amount of solution or the size of the electrodes.

The measured emf can be treated as the sum of the two electric potentials arising from the Zn and Cu electrodes.

Page 7: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

7

The value of the emf is independent of the amount of solution or the size of the electrodes.

The measured emf can be treated as the sum of the two electric potentials arising from the Zn and Cu electrodes.

It is impossible to measure the potential of a single electrode: any complete circuit must by necessity, contain two electrodes.

Page 8: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

8

The value of the emf is independent of the amount of solution or the size of the electrodes.

The measured emf can be treated as the sum of the two electric potentials arising from the Zn and Cu electrodes.

It is impossible to measure the potential of a single electrode: any complete circuit must by necessity, contain two electrodes.

A simple way out of this dilemma is to chose a certain electrode and arbitrarily set its potential value to zero volts.

Page 9: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

9

This electrode can then be used to determine the potentials of other electrodes by measuring the emf of various cells.

Page 10: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

10

This electrode can then be used to determine the potentials of other electrodes by measuring the emf of various cells.

The standard hydrogen electrode is chosen as the reference (abbreviated as SHE).

Page 11: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

11

This electrode can then be used to determine the potentials of other electrodes by measuring the emf of various cells.

The standard hydrogen electrode is chosen as the reference (abbreviated as SHE). The reaction is

2 H+(aq) + 2e- H2(g) E0 = 0 V

Page 12: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

12

This electrode can then be used to determine the potentials of other electrodes by measuring the emf of various cells.

The standard hydrogen electrode is chosen as the reference (abbreviated as SHE). The reaction is

2 H+(aq) + 2e- H2(g) E0 = 0 V

(1 M) (1 bar)

Page 13: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

13

This electrode can then be used to determine the potentials of other electrodes by measuring the emf of various cells.

The standard hydrogen electrode is chosen as the reference (abbreviated as SHE). The reaction is

2 H+(aq) + 2e- H2(g) E0 = 0 V

(1 M) (1 bar) The symbol for the emf is Ecell (some use just E).

Page 14: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

14

This electrode can then be used to determine the potentials of other electrodes by measuring the emf of various cells.

The standard hydrogen electrode is chosen as the reference (abbreviated as SHE). The reaction is

2 H+(aq) + 2e- H2(g) E0 = 0 V

(1 M) (1 bar) The symbol for the emf is Ecell (some use just E). The

superscript 0 denotes standard state conditions, which for the present case refers to H+

(aq) at 1 M, H2(g) at 1 bar, and a reference temperature of exactly 25 oC is assumed.

Page 15: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

15

For a half-cell reaction at standard conditions, the notation E0 is employed. Other notation that is employed is or sometimes , this latter one signifying that it is a standard reduction potential.

Standard emf: The potential difference between two electrodes which can be measured for a given cell when all solutes are at a concentration of 1 M and all gases are at 1 bar.

0cell-halfE 0

redE

Page 16: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

16

Suppose we want to determine the for the reaction

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

then set up the cell with a SHE, so that:

anode: H2(g) 2 H+(aq) + 2e- = 0 V

cathode: Cu2+(aq) + 2 e- Cu(s) = ?

overall reaction: H2(g) + Cu2+(aq) 2 H+

(aq) + Cu(s)

= 0.34 V Since the two values must add to 0.34 V,

therefore = 0.34 V for the Cu2+ half-reaction.

0cell-halfE

0cell-halfE

0cell-halfE

0cellE

0cell-halfE

0cell-halfE

Page 17: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

17

Page 18: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

18

The standard electrode potential for the reaction

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

0cell-halfE

Page 19: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

19

The standard electrode potential for the reaction

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

can be measured with a SHE, so that:

0cell-halfE

Page 20: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

20

The standard electrode potential for the reaction

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

can be measured with a SHE, so that:

anode: Zn(s) Zn2+(aq) + 2 e- = ?

0cell-halfE

0cell-halfE

Page 21: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

21

The standard electrode potential for the reaction

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

can be measured with a SHE, so that:

anode: Zn(s) Zn2+(aq) + 2 e- = ?

cathode: 2 H+(aq) + 2e- H2(g) = 0 V

0cell-halfE

0cell-halfE

0cell-halfE

Page 22: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

22

The standard electrode potential for the reaction

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

can be measured with a SHE, so that:

anode: Zn(s) Zn2+(aq) + 2 e- = ?

cathode: 2 H+(aq) + 2e- H2(g) = 0 V

overall reaction: 2 H+

(aq) + Zn(s) H2(g) + Zn2+(aq)

= 0.76 V

0cell-halfE

0cell-halfE

0cellE

0cell-halfE

Page 23: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

23

The standard electrode potential for the reaction

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

can be measured with a SHE, so that:

anode: Zn(s) Zn2+(aq) + 2 e- = ?

cathode: 2 H+(aq) + 2e- H2(g) = 0 V

overall reaction: 2 H+

(aq) + Zn(s) H2(g) + Zn2+(aq)

= 0.76 V Since the two values must add to 0.76 V,

therefore = 0.76 V for the Zn half-reaction.

0cell-halfE

0cell-halfE

0cellE

0cell-halfE

0cell-halfE

0cell-halfE

Page 24: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

24

Page 25: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

25

Page 26: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

26

Page 27: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

27

Standard reduction potential: The voltage associated with a reduction at an electrode when all solutes are 1 M and all gases are at 1 bar.

Page 28: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

28

Standard reduction potential: The voltage associated with a reduction at an electrode when all solutes are 1 M and all gases are at 1 bar.

It is most common to table information as reductions potentials.

0cell-halfE

Page 29: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

29

Page 30: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

30

Standard reduction potential: The voltage associated with a reduction at an electrode when all solutes are 1 M and all gases are at 1 bar.

It is most common to table information as reductions potentials.

Standard oxidation potential: The voltage associated with an oxidation at an electrode when all solutes are 1 M and all gases are at 1 bar.

0cell-halfE

Page 31: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

31

The standard oxidation potential for the Zn electrode reaction:

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

Page 32: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

32

The standard oxidation potential for the Zn electrode reaction:

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

is = 0.76 V

0cell-halfE

Page 33: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

33

The standard oxidation potential for the Zn electrode reaction:

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

is = 0.76 V When we reverse the half-cell reaction, we must

change the sign of .

0cell-halfE

0cell-halfE

Page 34: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

34

The standard oxidation potential for the Zn electrode reaction:

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

is = 0.76 V When we reverse the half-cell reaction, we must

change the sign of . Thus the standard reduction potential for the reaction:

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

0cell-halfE

0cell-halfE

Page 35: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

35

The standard oxidation potential for the Zn electrode reaction:

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

is = 0.76 V When we reverse the half-cell reaction, we must

change the sign of . Thus the standard reduction potential for the reaction:

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

is = -0.76 V

0cell-halfE

0cell-halfE

0cell-halfE

Page 36: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

36

Calculation of 0cellE

Page 37: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

37

Calculation of Example: Calculate for the reaction Cu2+

(aq) + Zn(s) Zn2+(aq) + Cu(s)

assuming a table of is available.

0cellE

0cellE

0cell-halfE

Page 38: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

38

Calculation of Example: Calculate for the reaction Cu2+

(aq) + Zn(s) Zn2+(aq) + Cu(s)

assuming a table of is available. From the table of values the following is

available

0cellE

0cellE

0cell-halfE

0cell-halfE

Page 39: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

39

Calculation of Example: Calculate for the reaction Cu2+

(aq) + Zn(s) Zn2+(aq) + Cu(s)

assuming a table of is available. From the table of values the following is

available Zn2+

(aq) + 2 e- Zn(s) = -0.76 V

0cellE

0cellE

0cell-halfE

0cell-halfE

0cell-halfE

Page 40: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

40

Calculation of Example: Calculate for the reaction Cu2+

(aq) + Zn(s) Zn2+(aq) + Cu(s)

assuming a table of is available. From the table of values the following is

available Zn2+

(aq) + 2 e- Zn(s) = -0.76 V

Cu2+(aq) + 2 e- Cu(s) = 0.34 V

0cellE

0cellE

0cell-halfE

0cell-halfE

0cell-halfE

0cell-halfE

Page 41: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

41

The overall reaction is stripped down to the two half-equations:

Page 42: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

42

The overall reaction is stripped down to the two half-equations:

Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

Page 43: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

43

The overall reaction is stripped down to the two half-equations:

Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

Cu2+(aq) + 2 e- Cu(s) = 0.34 V

0cell-halfE

Page 44: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

44

The overall reaction is stripped down to the two half-equations:

Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

Cu2+(aq) + 2 e- Cu(s) = 0.34 V

Zn(s) Zn2+(aq) + 2 e- = 0.76 V

0cell-halfE

0cell-halfE

Page 45: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

45

The overall reaction is stripped down to the two half-equations:

Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

Cu2+(aq) + 2 e- Cu(s) = 0.34 V

Zn(s) Zn2+(aq) + 2 e- = 0.76 V

Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s) = 1.10 V

0cellE

0cell-halfE

0cell-halfE

Page 46: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

46

The overall reaction is stripped down to the two half-equations:

Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

Cu2+(aq) + 2 e- Cu(s) = 0.34 V

Zn(s) Zn2+(aq) + 2 e- = 0.76 V

Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s) = 1.10 V

This is the simplest approach to calculate values, and the approach I recommend using.

0cellE

0cell-halfE

0cell-halfE

0cellE

Page 47: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

47

There is an alternative approach, that is based on the formula:

where and are the values for the cathode and anode reactions, pulled directly from a standard table of reduction potentials.

0redanode,

0redcathode,

0cell EEE

0redcathode,E 0

redanode,E 0cell-halfE

Page 48: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

48

There is an alternative approach, that is based on the formula:

where and are the values for the cathode and anode reactions, pulled directly from a standard table of reduction potentials.

The reaction Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

has the two half-cell reactions:

0redanode,

0redcathode,

0cell EEE

0redcathode,E 0

redanode,E 0cell-halfE

Page 49: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

49

There is an alternative approach, that is based on the formula:

where and are the values for the cathode and anode reactions, pulled directly from a standard table of reduction potentials.

The reaction Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

has the two half-cell reactions: anode: Zn(s) Zn2+

(aq) + 2 e-

0redanode,

0redcathode,

0cell EEE

0redcathode,E 0

redanode,E 0cell-halfE

Page 50: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

50

There is an alternative approach, that is based on the formula:

where and are the values for the cathode and anode reactions, pulled directly from a standard table of reduction potentials.

The reaction Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

has the two half-cell reactions: anode: Zn(s) Zn2+

(aq) + 2 e-

cathode: Cu2+(aq) + 2 e- Cu(s)

0redanode,

0redcathode,

0cell EEE

0redcathode,E 0

redanode,E 0cell-halfE

Page 51: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

51

There is an alternative approach, that is based on the formula:

where and are the values for the cathode and anode reactions, pulled directly from a standard table of reduction potentials.

The reaction Cu2+(aq) + Zn(s) Zn2+

(aq) + Cu(s)

has the two half-cell reactions: anode: Zn(s) Zn2+

(aq) + 2 e-

cathode: Cu2+(aq) + 2 e- Cu(s)

Therefore 0.34 V – (–0.76 V) = 1.10 V

0redanode,

0redcathode,

0cell EEE

0redcathode,E 0

redanode,E 0cell-halfE

0cellE

Page 52: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

52

A large number of mistakes are made when using this approach. The most common one is that the reaction involving Zn is an oxidation, so students reverse the sign of the value in the table for the Zn half-reaction, but retain the minus sign in the formula, thereby getting the wrong answer of

-0.42 V.

Page 53: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

53

Spontaneity of Redox Reactions

Page 54: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

54

Spontaneity of Redox Reactions Under standard state conditions, a redox reaction is

spontaneous in the forward direction if the standard emf of the cell is positive.

Page 55: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

55

Spontaneity of Redox Reactions Under standard state conditions, a redox reaction is

spontaneous in the forward direction if the standard emf of the cell is positive.

The more positive the value, the greater the tendency for the substance to be reduced. For example, F2(g) + 2 e- 2 F-

(aq) = 2.87 V,

is one of the largest values,

0cell-halfE

0cell-halfE

0cell-halfE

Page 56: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

56

Spontaneity of Redox Reactions Under standard state conditions, a redox reaction is

spontaneous in the forward direction if the standard emf of the cell is positive.

The more positive the value, the greater the tendency for the substance to be reduced. For example, F2(g) + 2 e- 2 F-

(aq) = 2.87 V,

is one of the largest values, which makes F2 one of the strongest oxidizing agents available.

0cell-halfE

0cell-halfE

0cell-halfE

Page 57: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

57

Li+(aq) + e- Li = - 3.05 V

0cell-halfE

Page 58: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

58

Li+(aq) + e- Li = - 3.05 V

This reaction has the one of the most negative values, making Li+ one of the weakest oxidizing

agents.

0cell-halfE

0cell-halfE

Page 59: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

59

Li+(aq) + e- Li = - 3.05 V

This reaction has the one of the most negative values, making Li+ one of the weakest oxidizing

agents. If we reverse the reaction: Li Li+

(aq) + e- = 3.05 V

0cell-halfE

0cell-halfE

0cell-halfE

Page 60: Standard Electrode Potentials When the concentrations of Cu 2+ (aq) and Zn 2+ (aq) are both kept at unit activity, the emf of the galvanic cell is 1.10

60

Li+(aq) + e- Li = - 3.05 V

This reaction has the one of the most negative values, making Li+ one of the weakest oxidizing

agents. If we reverse the reaction: Li Li+

(aq) + e- = 3.05 V

Li is one of the strongest reducing agents available.

0cell-halfE

0cell-halfE

0cell-halfE


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NaCl (aq) + Mg(NO3)2 (aq) NaNO3 (aq) + MgCl2 (aq) 2

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CHEMISTRY 161 Chapter 4. REVISION HCl(aq) + NaOH(aq) → NaCl(aq) + H 2 O(l) H + (aq) + OH - (aq) → H 2 O(l) (Arrhenius) HCl(aq) + NH 3 (aq) → NH 4 Cl(aq)

Galvanic Corr

Redox Reactions in Batteries 253...Lead-Acid •1859 Gaston Plante’ •Discharge –Galvanic Cell (Spontaneous) •Negative plate: •Pb(0)(s) + HSO 4-(aq) Pb(II)SO4 (s) + H +(aq)

Galvanic corrrosion.doc

Galvanic Spa

Galvanic Faq

Eastman AQTM polymers · 4 Aqueous dispersion clarity AQ 48 . AQ 55 . AQ 38 Solvent tolerance AQ 48 . AQ 38 . AQ 55 Water resistance AQ 55 5 AQ 38 . AQ 48 Eastman AQ linear polyesters

Galvanic Overview

Galvanic currents

CH3CH2COOH(aq) + H2O(l) CH3CH2COO-(aq) + H3O+(aq)

Galvanic Corrosion2

Fe 3+ (aq) + SCN - (aq) Fe(SCN) 2+ (aq) colorless

Galvanic Corrosion3

Galvanic Cell

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WJE Primer: Galvanic Corrosion · PDF filegreater galvanic action. ... (Statue of Liberty) ... WJE Primer: Galvanic Corrosion Author: Elise Love \(WJE\) Subject: Galvanic Corrosion

Galvanic current

AQ-1. AQ-2, AQ-3, AQ-4, AQ-5

aQ-...aQ- ... 2

Galvanic 2

Galvanic Cell WS Answer Key - Weeblycollisonchemistry.weebly.com/uploads/3/8/2/4/38246343/...The reaction Sn2+(aq) + Zn(s) Sn(s) + Zn2+(aq) is used to run the galvanic cell, below

Electrochemistry Voltaic Cells Voltaic (Galvanic) Cells - spontaneous reaction used to produce electrical energy. Salt Bridge Cells Zn(s) + Cu 2+ (aq)

Galvanic Cells

ELECTROCHEMISTRY 2 GALVANIC CELLS AND CELL …drsapnag.manusadventures.com/chemistry/general-chemistry/general... · ELECTROCHEMISTRY –2 GALVANIC CELLS AND CELL POTENTIAL ... GALVANIC