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Presentation on theme: "Electrochemistry."— Presentation transcript:

1 Electrochemistry

2 Electrochemistry Study of the interchange of chemical and electrical energy …

3 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ...

4 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ...

5 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ...

6 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ...

7 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ...

8 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent …

9 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ...

10 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ...

11 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ...

12 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent …

13 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ...

14 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge

15 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) …

16 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ...

17 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ... electroactve solutions remain separated …

18 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ... electroactve solutions remain separated … Electromotive force (emf) ...

19 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ... electroactve solutions remain separated … Electromotive force (emf) ...

20 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ... electroactve solutions remain separated … Electromotive force (emf) ... the driving force with which electrons are pulled through a wire ...

21 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ... electroactve solutions remain separated … Electromotive force (emf) ... the driving force with which electrons are pulled through a wire ... Volt (V) ...

22 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ... electroactve solutions remain separated … Electromotive force (emf) ... the driving force with which electrons are pulled through a wire ... Volt (V) ... the unit of electrical potential …

23 Electrochemistry Study of the interchange of chemical and electrical energy … Galvanic Cells ... Devices in which chemical energy is converted into electrical energy ... Cathode ... Reduction occurs here ... Species undergoing reduction ... a.k.a. oxidizing agent … receives electrons from the cathode ... Anode ... Oxidation occurs here ... aka reducing agent … gives up electrons to cathode here ... Salt bridge (or porous disk) … allows flow of electrons to keep electrical neutrality ... electroactve solutions remain separated … Electromotive force (emf) ... the driving force with which electrons are pulled through a wire ... Volt (V) ... the unit of electrical potential … it equals 1 Joule/coulomb ...

24 Electrochemistry Direction of electron flow in Galvanic Cells …

25 Electrochemistry Direction of electron flow in Galvanic Cells … From anaode to cathode ...

26 Electrochemistry Direction of electron flow in Galvanic Cells … From anaode to cathode ... FATCAT ...

27 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ...

28 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ...

29 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ... Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)

30 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ... Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l)

31 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ... Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown:

32 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ... Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ...

33 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ... Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution:

34 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ... Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive e-1 at cathode ...

35 Electrochemistry Direction of electron flow in Galvanic Cells … From anode to cathode ... FATCAT ... Species undergoing reduction receive electrons from the cathode ... Species undergoing oxidation donate electrons to the anode ... Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ...

36 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode):

37 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1

38 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1 Reduction (cathode):

39 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1 Reduction (cathode): 2H+(aq) + 2e > H2(g)

40 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1 Reduction (cathode): 2H+(aq) + 2e > H2(g)

41 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1 Reduction (cathode): 2H+(aq) + 2e > H2(g) b. Oxidation (anode):

42 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1 Reduction (cathode): 2H+(aq) + 2e > H2(g) b. Oxidation (anode): 5Fe+2(aq) ----> 5Fe+3(aq) + 5e-1

43 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1 Reduction (cathode): 2H+(aq) + 2e > H2(g) b. Oxidation (anode): 5Fe+2(aq) ----> 5Fe+3(aq) + 5e-1 Reduction (cathode):

44 Electrochemistry Known: a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)
b. MnO4-1(aq) + 5Fe+2(aq) + 8H+(aq) ---> Mn+2(aq) + 5Fe+3(aq) + 4H2O(l) Unknown: Identify the species that would receive electrons from the cathode and which would lose electrons at the anode in each of the following galvanic cells ... Solution: reduction ½ rxs receive cathode ... oxidation ½ rxs. lose anode ... a. Oxidation (anode): Mg(s) ----> Mg+2(aq) + 2e-1 Reduction (cathode): 2H+(aq) + 2e > H2(g) b. Oxidation (anode): 5Fe+2(aq) ----> 5Fe+3(aq) + 5e-1 Reduction (cathode): MnO4-1(aq) + 8H+(aq) + 5e > Mn+2(aq) + 4H2O(l)

45 Electrochemistry Standard Reduction Potentials …

46 Electrochemistry Standard Reduction Potentials …
Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ...

47 Electrochemistry Standard Reduction Potentials …
Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ...

48 Electrochemistry Standard Reduction Potentials …
Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ...

49 Electrochemistry Standard Reduction Potentials …
Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ... The standard is the standard hydrogen electrode ...

50 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V
Electrochemistry Standard Reduction Potentials … Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ... The standard is the standard hydrogen electrode ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V

51 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry Standard Reduction Potentials … Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ... The standard is the standard hydrogen electrode ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)

52 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry Standard Reduction Potentials … Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ... The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)

53 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry Standard Reduction Potentials … Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ... The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ...

54 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry Standard Reduction Potentials … Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ... The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ...

55 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry Standard Reduction Potentials … Electromotive force (emf) of a galvanic cell is a combination of the potentials of the two half-reactions ... Cathodic potentials are described relative to anodic reactions ... An absolute standard against which all other half-reactions can be compared is required ... The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation …

56 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation …

57 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation … To determine which reaction is to be reversed ...

58 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation … To determine which reaction is to be reversed ... the sum of the oxidation and reduction half-reactions must be > 0 in a galvanic cell …

59 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation … To determine which reaction is to be reversed ... the sum of the oxidation and reduction half-reactions must be > 0 in a galvanic cell … When you reverse a reaction ...

60 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation … To determine which reaction is to be reversed ... the sum of the oxidation and reduction half-reactions must be > 0 in a galvanic cell … When you reverse a reaction ... E’ gets the opposite sign ...

61 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation … To determine which reaction is to be reversed ... the sum of the oxidation and reduction half-reactions must be > 0 in a galvanic cell … When you reverse a reaction ... E’ gets the opposite sign ... When you multiply a reaction by a coefficient (for purposes of balancing) ...

62 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition)
Electrochemistry The standard is the standard hydrogen electrode K & 1 atm ... 2H+(aq) + 2e-1 ---> H2(g) E’ = 0.00 V (exactly, by definition) Galvanic cells require E’cell > 0 ... One of the tabulated cell potentials have to be reversed ... to form an oxidation half-reaction in EVERY E’ calculation … To determine which reaction is to be reversed ... the sum of the oxidation and reduction half-reactions must be > 0 in a galvanic cell … When you reverse a reaction ... E’ gets the opposite sign ... When you multiply a reaction by a coefficient (for purposes of balancing) ... E’ is not changed ...

63 Electrochemistry Cell Emf …

64 Electrochemistry Cell Emf … Known:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g)

65 Electrochemistry Cell Emf … Known:
Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq)

66 Electrochemistry Cell Emf … Known:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l)

67 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l)

68 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l)

69 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution:

70 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs …

71 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ...

72 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction:

73 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g)

74 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = 0.00 V

75 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = 0.00 V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1

76 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = 0.00 V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V

77 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V

78 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic)

79 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s)

80 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V

81 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1

82 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V

83 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V

84 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V

85 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic)

86 Electrochemistry Cell Emf … Known: Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic) Note: will not run in this direction ...

87 Electrochemistry Known: Cell Emf … Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic) Note: will not run in this direction ... c. Reduction: 2Zn+2(aq) + 4e > 2Zn(s)

88 Electrochemistry Known: Cell Emf … Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic) Note: will not run in this direction ... c. Reduction: 2Zn+2(aq) + 4e > 2Zn(s) E’ = V

89 Electrochemistry Known: Cell Emf … Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic) Note: will not run in this direction ... c. Reduction: 2Zn+2(aq) + 4e > 2Zn(s) E’ = V Oxidation: 4OH-1(aq) ----> O2(g) + 2H2O(l) + 4e-1

90 Electrochemistry Known: Cell Emf … Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic) Note: will not run in this direction ... c. Reduction: 2Zn+2(aq) + 4e > 2Zn(s) E’ = V Oxidation: 4OH-1(aq) ----> O2(g) + 2H2O(l) + 4e-1 E’ = V

91 Electrochemistry Known: Cell Emf … Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic) Note: will not run in this direction ... c. Reduction: 2Zn+2(aq) + 4e > 2Zn(s) E’ = V Oxidation: 4OH-1(aq) ----> O2(g) + 2H2O(l) + 4e-1 E’ = V E’cell = V

92 Electrochemistry Known: Cell Emf … Unknown:
a. Mg(s) + 2H+(aq) ----> Mg+2(aq) + H2(g) E’cell = ? V b. Cu+2(aq) + 2Ag(s) ----> Cu(s) + 2Ag+1(aq) Galvanic? c. 2Zn+2(aq) + 4OH-1(aq) ----> 2Zn(aq) + O2(g) + 2H2O(l) Solution: Split each rx into two ½ rxs … look up cell potentials ... a. reduction: 2H+(aq) + 2e > H2(g) E’ = V oxidation: Mg(s) ----> Mg+2(aq) + 2e-1 E’ = V E’cell = V (Galvanic) b. reduction: Cu+2(aq) + 2e > Cu(s) E’ = V oxidation: 2Ag(s) ----> 2Ag+1(aq) + 2e-1 E’ = V E’cell = V (Not Galvanic) Note: will not run in this direction ... c. Reduction: 2Zn+2(aq) + 4e > 2Zn(s) E’ = V Oxidation: 4OH-1(aq) ----> O2(g) + 2H2O(l) + 4e-1 E’ = V E’cell = V (Not Gal)

93 Electrochemistry Key Point …

94 Electrochemistry Key Point … The more positive the E’ Value ...

95 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced …

96 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ...

97 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ... The more negative the E’ Value ...

98 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ... The more negative the E’ Value ... the more likely the species is to be oxidized …

99 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ... The more negative the E’ Value ... the more likely the species is to be oxidized … it is a stronger reducing agent ...

100 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ... The more negative the E’ Value ... the more likely the species is to be oxidized … it is a stronger reducing agent ... Ex: Reduction: Br2(l)+ 2e > 2Br-1(aq) E’ = V

101 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ... The more negative the E’ Value ... the more likely the species is to be oxidized … it is a stronger reducing agent ... Ex: Reduction: Br2(l)+ 2e > 2Br-1(aq) E’ = V Oxidation: 2I > I2(l) + 2e-1 E’ = V

102 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ... The more negative the E’ Value ... the more likely the species is to be oxidized … it is a stronger reducing agent ... Ex: Reduction: Br2(l)+ 2e > 2Br-1(aq) E’ = V Oxidation: 2I > I2(l) + 2e-1 E’ = V

103 Electrochemistry Key Point …
The more positive the E’ Value ... the more likely the species is to be reduced … it is a stronger oxidizing agent ... The more negative the E’ Value ... the more likely the species is to be oxidized … it is a stronger reducing agent ... Ex: Reduction: Br2(l)+ 2e > 2Br-1(aq) E’ = V Oxidation: 2I > I2(l) + 2e-1 E’ = V E’cell = +.55 V

104 Electrochemistry Known: Reduction Strength

105 Electrochemistry Known: Reduction Strength
Fe+2(aq) + 2e > Fe(s) E’ = V

106 Electrochemistry Known: Reduction Strength
Fe+2(aq) + 2e > Fe(s) E’ = V ClO2(aq) + e > ClO2-1(aq) E’ = V

107 Electrochemistry Known: Reduction Strength
Fe+2(aq) + 2e > Fe(s) E’ = V ClO2(aq) + e > ClO2-1(aq) E’ = V F2(l) + 2e > 2F-1(aq) E’ = V

108 Electrochemistry Known: Reduction Strength
Fe+2(aq) + 2e > Fe(s) E’ = V ClO2(aq) + e > ClO2-1(aq) E’ = V F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V

109 Electrochemistry Known: Reduction Strength Unknown:
Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of strength as ClO2(aq) + e > ClO2-1(aq) E’ = V oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V

110 Electrochemistry Known: Reduction Strength Unknown:
Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of strength as ClO2(aq) + e > ClO2-1(aq) E’ = V oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V Solution: good oxidizing agents are more likely to be in reduced state as they readily strip electrons from other substances …

111 Electrochemistry Known: Reduction Strength Unknown:
Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of strength as ClO2(aq) + e > ClO2-1(aq) E’ = V oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V Solution: good oxidizing agents are more likely to be in reduced state as they readily strip electrons from other substances … the more positive the E’ value ...

112 Electrochemistry Known: Reduction Strength Unknown:
Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of increasing ClO2(aq) + e > ClO2-1(aq) E’ = V strength as oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V Solution: good oxidizing agents are more likely to be in reduced state as they readily strip electrons from other substances … the more positive the E’ value ... the more likely a substance will be in reduced form …

113 Electrochemistry Known: Reduction Strength Unknown:
Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of increasing ClO2(aq) + e > ClO2-1(aq) E’ = V strength as oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V Solution: good oxidizing agents are more likely to be in reduced state as they readily strip electrons from other substances … the more positive the E’ value ... the more likely a substance will be in reduced form … Fe+2 <

114 Electrochemistry Known: Reduction Strength Unknown:
Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of increasing ClO2(aq) + e > ClO2-1(aq) E’ = V strength as oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V Solution: good oxidizing agents are more likely to be in reduced state as they readily strip electrons from other substances … the more positive the E’ value ... the more likely a substance will be in reduced form … Fe+2 < AgCl <

115 Fe+2 < AgCl < ClO2 <
Electrochemistry Known: Reduction Strength Unknown: Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of increasing ClO2(aq) + e > ClO2-1(aq) E’ = V strength as oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V Solution: good oxidizing agents are more likely to be in reduced state as they readily strip electrons from other substances … the more positive the E’ value ... the more likely a substance will be in reduced form … Fe+2 < AgCl < ClO2 <

116 Fe+2 < AgCl < ClO2 < F2
Electrochemistry Known: Reduction Strength Unknown: Fe+2(aq) + 2e > Fe(s) E’ = V Rank in order of increasing ClO2(aq) + e > ClO2-1(aq) E’ = V strength as oxidizing agent … F2(l) + 2e > 2F-1(aq) E’ = V AgCl(s) + e > Ag(s) + Cl-1(aq) E’ = V Solution: good oxidizing agents are more likely to be in reduced state as they readily strip electrons from other substances … the more positive the E’ value ... the more likely a substance will be in reduced form … Fe+2 < AgCl < ClO2 < F2

117 Electrochemistry Composing Galvanic Cells …

118 Electrochemistry Composing Galvanic Cells … Known:
a. Ni+2 + 2e > Ni E’ = V

119 Electrochemistry Composing Galvanic Cells … Known:
a. Ni+2 + 2e > Ni E’ = V O2 + 4H+1 + 4e >2H2O E’ = V

120 Electrochemistry Composing Galvanic Cells … Known:
a. Ni+2 + 2e > Ni E’ = V O2 + 4H+1 + 4e >2H2O E’ = V b. Ce+4 + e > Ce+3 E’ = V

121 Electrochemistry Composing Galvanic Cells … Known:
a. Ni+2 + 2e > Ni E’ = V O2 + 4H+1 + 4e >2H2O E’ = V b. Ce+4 + e > Ce+3 E’ = V Sn+2 + 2e > Sn E’ = V

122 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V b. Ce+4 + e > Ce+3 E’ = V Sn+2 + 2e > Sn E’ = V

123 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? b. Ce+4 + e > Ce+3 E’ = V Sn+2 + 2e > Sn E’ = V

124 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Sn+2 + 2e > Sn E’ = V

125 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V

126 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution:

127 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... a. Reversing Ni+2 will create a galvanic cell …

128 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... a. Reversing Ni+2 will create a galvanic cell … Cathode: O2 + 4H+1 + 4e >2H2O E’ = V

129 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... a. Reversing Ni+2 will create a galvanic cell … multiple Ni+2 by 2 ... Cathode: O2 + 4H+1 + 4e >2H2O E’ = V

130 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... a. Reversing Ni+2 will create a galvanic cell … multiple Ni+2 by 2 ... cathode: O2 + 4H+1 + 4e >2H2O E’ = V anode: 2Ni ----> 2Ni+2 + 4e-1 E’ = V

131 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... a. Reversing Ni+2 will create a galvanic cell … multiple Ni+2 by 2 ... cathode: O2 + 4H+1 + 4e >2H2O E’ = V anode: 2Ni ----> 2Ni+2 + 4e-1 E’ = V overall: O2 + 4H+1 + 2Ni ----> 2Ni+2 + 2H2O

132 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... a. Reversing Ni+2 will create a galvanic cell … multiple Ni+2 by 2 ... cathode: O2 + 4H+1 + 4e >2H2O E’ = V anode: 2Ni ----> 2Ni+2 + 4e-1 E’ = V overall: O2 + 4H+1 + 2Ni ----> 2Ni+2 + 2H2O E’cell = V

133 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... b. Reversing Sn+2 reaction will create a galvanic cell …

134 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... b. Reversing Sn+2 reaction will create a galvanic cell … multiply Ce+4 by 2 ... cathode: 2Ce+4 + 2e > 2Ce+3 E’ = V

135 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... b. Reversing Sn+2 reaction will create a galvanic cell … multiply Ce+4 by 2 ... cathode: 2Ce+4 + 2e > 2Ce+3 E’ = V anode: Sn ----> Sn+2 + 2e-1 E’ = V

136 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... b. Reversing Sn+2 reaction will create a galvanic cell … multiply Ce+4 by 2 ... cathode: 2Ce+4 + 2e > 2Ce+3 E’ = V anode: Sn ----> Sn+2 + 2e-1 E’ = V

137 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... b. Reversing Sn+2 reaction will create a galvanic cell … multiply Ce+4 by 2 ... cathode: 2Ce+4 + 2e > 2Ce+3 E’ = V anode: Sn ----> Sn+2 + 2e-1 E’ = V overall rx: 2Ce+4 + Sn ----> Sn+2 + 2Ce+3

138 Electrochemistry Composing Galvanic Cells … Known: Unknown:
a. Ni+2 + 2e > Ni E’ = V Anode? O2 + 4H+1 + 4e >2H2O E’ = V Cathode? Balance ... b. Ce+4 + e > Ce+3 E’ = V Write Overall Cell Rx ... Sn+2 + 2e > Sn E’ = V Calculate E’cell Solution: Goal ... Which arrangement will make E’cell > 0 ... b. Reversing Sn+2 reaction will create a galvanic cell … multiply Ce+4 by 2 ... cathode: 2Ce+4 + 2e > 2Ce+3 E’ = V anode: Sn ----> Sn+2 + 2e-1 E’ = V overall rx: 2Ce+4 + Sn ----> Sn+2 + 2Ce+3 E’cell = V

139 Electrochemistry Line Notation ...

140 Electrochemistry Line Notation ... A method of representing electrochemical cells ...

141 Electrochemistry Line Notation ... A method of representing electrochemical cells ... shorthand notation used to describe galvanic cells ...

142 Electrochemistry Line Notation ... A method of representing electrochemical cells ... shorthand notation used to describe galvanic cells ... The general line notation formation is ...

143 anode side || cathode side
Electrochemistry Line Notation ... A method of representing electrochemical cells ... shorthand notation used to describe galvanic cells ... The general line notation formation is ... anode side || cathode side Porous disk or Salt bridge

144 anode side || cathode side
Electrochemistry Line Notation ... A method of representing electrochemical cells ... shorthand notation used to describe galvanic cells ... The general line notation formation is ... anode side || cathode side Porous disk or Salt bridge Each side will have a phase boundary separating, e.g., a solid electrode from ions in solution …

145 anode side || cathode side
Electrochemistry Line Notation ... A method of representing electrochemical cells ... shorthand notation used to describe galvanic cells ... The general line notation formation is ... anode side || cathode side Porous disk or Salt bridge Each side will have a phase boundary separating, e.g., a solid electrode from ions in solution … such as Cu(s) and Cu+2(aq) ...

146 anode side || cathode side
Electrochemistry Line Notation ... A method of representing electrochemical cells ... shorthand notation used to describe galvanic cells ... The general line notation formation is ... anode side || cathode side Porous disk or Salt bridge Each side will have a phase boundary separating, e.g., a solid electrode from ions in solution … such as Cu(s) and Cu+2(aq) ... denoted by a single vertical line (“|”) with the solid phase on the outside …

147 Electrochemistry Consider the reaction between copper and zinc ...

148 Electrochemistry Consider the reaction between copper and zinc ...
anode: (oxidation) Zn ----> Zn+2 + 2e-1

149 Electrochemistry Consider the reaction between copper and zinc ...
anode: (oxidation) Zn ----> Zn+2 + 2e-1 cathode: (reduction) Cu+2 + 2e > Cu

150 Electrochemistry Consider the reaction between copper and zinc ...
anode: (oxidation) Zn ----> Zn+2 + 2e-1 cathode: (reduction) Cu+2 + 2e > Cu The line notation is ...

151 Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s)
Electrochemistry Consider the reaction between copper and zinc ... anode: (oxidation) Zn ----> Zn+2 + 2e-1 cathode: (reduction) Cu+2 + 2e > Cu The line notation is ... Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s)

152 Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s)
Electrochemistry Consider the reaction between copper and zinc ... anode: (oxidation) Zn ----> Zn+2 + 2e-1 cathode: (reduction) Cu+2 + 2e > Cu The line notation is ... Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s) Note: On occasion ...

153 Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s)
Electrochemistry Consider the reaction between copper and zinc ... anode: (oxidation) Zn ----> Zn+2 + 2e-1 cathode: (reduction) Cu+2 + 2e > Cu The line notation is ... Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s) Note: On occasion ... only ions (rather than solids) ...

154 Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s)
Electrochemistry Consider the reaction between copper and zinc ... anode: (oxidation) Zn ----> Zn+2 + 2e-1 cathode: (reduction) Cu+2 + 2e > Cu The line notation is ... Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s) Note: On occasion ... only ions (rather than solids) ... Will be involved in the redox process ...

155 Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s)
Electrochemistry Consider the reaction between copper and zinc ... anode: (oxidation) Zn ----> Zn+2 + 2e-1 cathode: (reduction) Cu+2 + 2e > Cu The line notation is ... Zn(s) | Zn+2(aq) || Cu+2(aq) | Cu(s) Note: On occasion ... only ions (rather than solids) ... Will be involved in the redox process ... in those cases “inert’ ecltrodes are used ...

156 Electrochemistry More on line notations …

157 Electrochemistry More on line notations … write line notations for the following galvanic cells ...

158 Electrochemistry More on line notations … write line notations for the following galvanic cells ...

159 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2

160 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1

161 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg

162 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s)

163 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2

164 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2 anode: Pb ----> Pb+2 + 2e-1

165 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2 anode: Pb ----> Pb+2 + 2e-1 cathode: 2Cr+3 + 2e > 2 Cr+2

166 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2 anode: Pb ----> Pb+2 + 2e-1 cathode: 2Cr+3 + 2e > 2 Cr+2 line notation: Pb(s)| Pb+2(aq) || Cr+3(aq) , Cr+2(aq) | Pt(s)

167 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2 anode: Pb ----> Pb+2 + 2e-1 cathode: 2Cr+3 + 2e > 2 Cr+2 line notation: Pb(s)| Pb+2(aq) || Cr+3(aq) , Cr+2(aq) | Pt(s) Cu+2 + 2Pu+4 + 4H2O -----> Cu + 2PuO H+1

168 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2 anode: Pb ----> Pb+2 + 2e-1 cathode: 2Cr+3 + 2e > 2 Cr+2 line notation: Pb(s)| Pb+2(aq) || Cr+3(aq) , Cr+2(aq) | Pt(s) Cu+2 + 2Pu+4 + 4H2O -----> Cu + 2PuO H+1 anode: 2Pu+4 + 4H2O ----> 2PuO H+1 + 2e-1

169 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2 anode: Pb ----> Pb+2 + 2e-1 cathode: 2Cr+3 + 2e > 2 Cr+2 line notation: Pb(s)| Pb+2(aq) || Cr+3(aq) , Cr+2(aq) | Pt(s) Cu+2 + 2Pu+4 + 4H2O -----> Cu + 2PuO H+1 anode: 2Pu+4 + 4H2O ----> 2PuO H+1 + 2e-1 cathode: Cu+2 + 2e > Cu

170 Electrochemistry More on line notations … write line notations for the following galvanic cells ... Hg+2 + Cd ----> Hg + Cd+2 anode: Cd ----> Cd+2 + 2e-1 cathode: Hg+2 + 2e > Hg line notation: Cd(s)| Cd+2(aq) || Hg+2(aq) | Hg(s) Pb + 2Cr > Pb+2 + 2Cr+2 anode: Pb ----> Pb+2 + 2e-1 cathode: 2Cr+3 + 2e > 2 Cr+2 line notation: Pb(s)| Pb+2(aq) || Cr+3(aq) , Cr+2(aq) | Pt(s) Cu+2 + 2Pu+4 + 4H2O -----> Cu + 2PuO H+1 anode: 2Pu+4 + 4H2O ----> 2PuO H+1 + 2e-1 cathode: Cu+2 + 2e > Cu line notation: Pt|Pu+4, PuO2+1, H+1 || Cu+2 | Cu

171 Electrochemistry Describing Galvanic Cells …

172 Electrochemistry Describing Galvanic Cells …
Cu+2 + 2e > Cu E’ = V

173 Electrochemistry Describing Galvanic Cells …
Cu+2 + 2e > Cu E’ = V Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V 1st: E’cell > 0 ...

174 Electrochemistry Describing Galvanic Cells …
Cu+2 + 2e > Cu E’ = V Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V 1st: E’cell > 0 ... anode: 3Cu ----> 3Cu+2 + 6e-1 E’ = V

175 Electrochemistry Describing Galvanic Cells …
Cu+2 + 2e > Cu E’ = V Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V 1st: E’cell > 0 ... anode: 3Cu ----> 3Cu+2 + 6e-1 E’ = V cathode: Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V

176 Electrochemistry Describing Galvanic Cells …
Cu+2 + 2e > Cu E’ = V Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V 1st: E’cell > 0 ... anode: 3Cu ----> 3Cu+2 + 6e E’ = V cathode: Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V overall rx: 3Cu(s) + Cr2O7-2(aq) + 14H+1(aq) ----> 3Cu+2(aq) + 2Cr+3(aq) + 7H2O(l) E’ = V

177 Electrochemistry Describing Galvanic Cells …
Cu+2 + 2e > Cu E’ = V Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V 1st: E’cell > 0 ... anode: 3Cu ----> 3Cu+2 + 6e E’ = V cathode: Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V overall rx: 3Cu(s) + Cr2O7-2(aq) + 14H+1(aq) ----> 3Cu+2(aq) + 2Cr+3(aq) + 7H2O(l) E’cell = V Line notation: Cu(s) | Cu+2(aq) || Cr2O7-2(aq) , Cr+3(aq) , H+1(aq) | Pt(s)

178 Electrochemistry Describing Galvanic Cells …
Cu+2 + 2e > Cu E’ = V Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V 1st: E’cell > 0 ... anode: 3Cu ----> 3Cu+2 + 6e E’ = V cathode: Cr2O H+1 + 6e > 2Cr+3 + 7H2O E’ = V overall rx: 3Cu(s) + Cr2O7-2(aq) + 14H+1(aq) ----> 3Cu+2(aq) + 2Cr+3(aq) + 7H2O(l) E’cell = V Line notation: Cu(s) | Cu+2(aq) || Cr2O7-2(aq) , Cr+3(aq) , H+1(aq) | Pt(s) Note: Electron flow is from Anode to Cathode, FATCAT, from Copper to Platinum ...

179 Electrochemistry Cell Potential, Electrical Work & Free Energy …

180 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ...

181 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not attainable) .... And cell potential ... ∆G = -nFE

182 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ...

183 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ... ∆G’ = -nFE’

184 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ... ∆G’ = -nFE’ Where ...

185 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ... ∆G’ = -nFE’ Where ... ∆G = free energy (J)

186 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ... ∆G’ = -nFE’ Where ... ∆G = free energy (J) n = moles of electrons exchanged in the redox reaction …

187 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ... ∆G’ = -nFE’ Where ... ∆G = free energy (J) n = moles of electrons exchanged in the redox reaction … F = Faraday, a constant (96,486 Coulombs per mole of electrons)

188 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ... ∆G’ = -nFE’ Where ... ∆G = free energy (J) n = moles of electrons exchanged in the redox reaction … F = Faraday, a constant (96,486 Coulombs per mole of electrons) E = cell voltage (J/C)

189 Electrochemistry Cell Potential, Electrical Work & Free Energy …
In general, the actual work that can be achieved is always less than the theoretical work available ... The relationship between free energy (maximum is assumed though not atainable) .... And cell potential ... ∆G = -nFE @ standard conditions ... ∆G’ = -nFE’ Where ... ∆G = free energy (J) n = moles of electrons exchanged in the redox reaction … F = Faraday, a constant (96,486 Coulombs per mole of electrons) E = cell voltage (J/C) Note: ∆G and E’ have opposite signs... for a spontaneous process ... ∆G is “-” & E’ = “+”

190 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq)

191 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ

192 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip?

193 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution:

194 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ...

195 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V

196 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V

197 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ ....

198 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ .... ∆G’ = ? kJ||

199 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ .... ∆G’ = ? kJ|| -nFE’ =

200 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ .... ∆G’ = ? kJ|| -nFE’ = -(2 mole-)(96,486 C/mole-)(-1.10 J/C) =

201 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ .... ∆G’ = ? kJ|| -nFE’ = -(2 mole-)(96,486 C/mole-)(-1.10 J/C) = 2.12 x 105 J

202 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ .... ∆G’ = ? kJ|| -nFE’ = -(2 mole-)(96,486 C/mole-)(-1.10 J/C) = 2.12 x 105 J = 212 kJ

203 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ .... ∆G’ = ? kJ|| -nFE’ = -(2 mole-)(96,486 C/mole-)(-1.10 J/C) = 2.12 x 105 J = 212 kJ Note: Zn+2 ions will not plate out on a Cu(s) at Standard Conditions ...

204 Electrochemistry Cell Potential, Electrical Work & Free Energy …
Known: Unknown: Zn+2(aq) + Cu(s) ----> Zn(s) + Cu+2(aq) ∆G’ = ? KJ Will Zn ions plate on Cu strip? Solution: 1st: Write the half-reactions ... oxidation rx: Cu(S) ----> Cu+2(aq) + 2e-1 E’ = V reduction rx: Zn+2(aq) + 2e > Zn(s) E’ = V E’cell = V 2nd: Calculate ∆G’ .... ∆G’ = ? kJ|| -nFE’ = -(2 mole-)(96,486 C/mole-)(-1.10 J/C) = 2.12 x 105 J = 212 kJ Note: Zn+2 ions will not plate out on a Cu(s) at Standard Conditions ... E’cell < 0

205 Electrochemistry Dependence of Cell Potential on Concentration …

206 Electrochemistry Dependence of Cell Potential on Concentration …
Concentration Cells ...

207 Electrochemistry Dependence of Cell Potential on Concentration …
Concentration Cells ... A cell in which current flows due only to a difference in concentration of an ion in two different compartments of a cell ...

208 Electrochemistry Dependence of Cell Potential on Concentration …
Concentration Cells ... A cell in which current flows due only to a difference in concentration of an ion in two different compartments of a cell ... Le Chatelier’s Principle is applicable here ...

209 Electrochemistry Dependence of Cell Potential on Concentration …
Concentration Cells ... A cell in which current flows due only to a difference in concentration of an ion in two different compartments of a cell ... Le Chatelier’s Principle is applicable here ... In a cell where there is an equal concentration of metal ions on both sides ...

210 Electrochemistry Dependence of Cell Potential on Concentration …
Concentration Cells ... A cell in which current flows due only to a difference in concentration of an ion in two different compartments of a cell ... Le Chatelier’s Principle is applicable here ... In a cell where there is an equal concentration of metal ions on both sides ... E’cell = 0 ...

211 Electrochemistry Concentration Cells …

212 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ...

213 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ...

214 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ...

215 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown:

216 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ...

217 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution:

218 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution: Current will flow until the [Cu+2] is equal in both compartments ...

219 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution: Current will flow until the [Cu+2] is equal in both compartments ... this means that the concentration of Cu+2 in the left-hand side (0.20 M) must be reduced by …

220 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution: Current will flow until the [Cu+2] is equal in both compartments ... this means that the concentration of Cu+2 in the left-hand side (0.02 M) must be reduced by … Cu+2 + 2e > Cu

221 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution: Current will flow until the [Cu+2] is equal in both compartments ... this means that the concentration of Cu+2 in the left-hand side (0.02 M) must be reduced by … Cu+2 + 2e > Cu The left-hand side will be the cathode ...

222 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution: Current will flow until the [Cu+2] is equal in both compartments ... this means that the concentration of Cu+2 in the left-hand side (0.02 M) must be reduced by … Cu+2 + 2e > Cu The left-hand side will be the cathode ... the right-hand side (0.050 M Cu+2) will be the anode …

223 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution: Current will flow until the [Cu+2] is equal in both compartments ... this means that the concentration of Cu+2 in the left-hand side (0.02 M) must be reduced by … Cu+2 + 2e > Cu The left-hand side will be the cathode ... the right-hand side (0.050 M Cu+2) will be the anode … current will flow from right to left ...

224 Electrochemistry Concentration Cells … Known:
A cell has on its left side a 0.20 M Cu+2 solution ... The right side has a M Cu+2 solution ... the compartments are connected by Cu electrodes and a salt bridge ... Unknown: Designate the cathode, anode, and direction of current ... Solution: Current will flow until the [Cu+2] is equal in both compartments ... this means that the concentration of Cu+2 in the left-hand side (0.02 M) must be reduced by … Cu+2 + 2e > Cu The left-hand side will be the cathode ... the right-hand side (0.050 M Cu+2) will be the anode … current will flow from right to left ... anode to cathode …

225 Electrochemistry Concentration Cells …

226 Electrochemistry Concentration Cells … produce a very small voltage ...

227 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ...

228 Ecell(nonstandard) =/ E’cell
Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell

229 Ecell(nonstandard) =/ E’cell
Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ...

230 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C)

231 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o

232 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o If [reactants]o > [products]o ....

233 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o If [reactants]o > [products]o .... log Q < 0 …

234 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o If [reactants]o > [products]o .... log Q < 0 … Ecell will be > E’cell ...

235 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o If [reactants]o > [products]o .... log Q < 0 … Ecell will be > E’cell ... consistent with Le Chatelier’s Principle and concentration cells ….

236 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o If [reactants]o > [products]o .... log Q < 0 … Ecell will be > E’cell ... consistent with Le Chatelier’s Principle and concentration cells …. When a battery is fully discharged ...

237 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o If [reactants]o > [products]o .... log Q < 0 … Ecell will be > E’cell ... consistent with Le Chatelier’s Principle and concentration cells …. When a battery is fully discharged ... it is at equilibrium ...

238 Electrochemistry Concentration Cells … produce a very small voltage ... nonstandard concentrations produce a cell voltage that is different from that at standard concentrations ... Ecell(nonstandard) =/ E’cell Nernst Equation ... Ecell = E’cell – (0.0592/n) log Q T = 25 ‘C) Where ... Q = [products]o / [reactants]o If [reactants]o > [products]o .... log Q < 0 … Ecell will be > E’cell ... consistent with Le Chatelier’s Principle and concentration cells …. When a battery is fully discharged ... it is at equilibrium ... Ecell =

239 Electrochemistry Nernst Equation ….

240 Electrochemistry Nernst Equation …. T = 25 ‘C

241 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
Cd+2 + 2e > Cd E’ = V

242 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
Cd+2 + 2e > Cd E’ = V Pb+2 + 2e > Pb E’ = V

243 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
Cd+2 + 2e > Cd E’ = V Pb+2 + 2e > Pb E’ = V [Cd+2] = M

244 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
Cd+2 + 2e > Cd E’ = V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M

245 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M

246 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ...

247 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V

248 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V

249 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s)

250 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V

251 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ...

252 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ... Ecell = ? V||

253 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ... Ecell = ? V|| E’cell – (0.0592/n) log Q

254 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ... Ecell = ? V|| E’cell – (0.0592/n) log Q = | E’cell – (0.0592/n) log [[Cd+1]/[Pb+2]] =

255 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ... Ecell = ? V|| E’cell – (0.0592/n) log Q = | E’cell – (0.0592/n) log [[Cd+1]/[Pb+2]] = = V – (0.0592/2)log [[0.010][0.100]]

256 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ... Ecell = ? V|| E’cell – (0.0592/n) log Q = | E’cell – (0.0592/n) log [[Cd+1]/[Pb+2]] = = V – (0.0592/2)log [[0.010][0.100]] = – (0.0296) log (0.10) =

257 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ... Ecell = ? V|| E’cell – (0.0592/n) log Q = | E’cell – (0.0592/n) log [[Cd+1]/[Pb+2]] = = V – (0.0592/2)log [[0.010][0.100]] = – (0.0296) log (0.10) = +0.30V

258 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
Cd+2 + 2e > Cd E’ = V Ecell = ? V Pb+2 + 2e > Pb E’ = V [Cd+2] = M [Pb+2] = M Solution: 1st: Ecell > 0 V to be Galvanic ... Cd ----> Cd+2 + 2e-1 E’ = V Pb+2 + 2e > Pb E’ = V Cd(s) + Pb+2(aq) ----> Cd+2(aq) + Pb(s) E’cell = V 2nd: Calculate nonstandard conditions ... Ecell = ? V|| E’cell – (0.0592/n) log Q = | E’cell – (0.0592/n) log [[Cd+1]/[Pb+2]] = = V – (0.0592/2)log [[0.010][0.100]] = – (0.0296) log (0.10)

259 Electrochemistry Nernst Equation …. T = 25 ‘C

260 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V

261 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V

262 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M

263 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [Fe+3] = 1.0 x 10-3 M

264 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M

265 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2

266 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2

267 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution:

268 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ...

269 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ...

270 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ2 will be oxidized ...

271 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ2 will be oxidized ... EQ1 is multiplied by 4 ...

272 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ2 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by

273 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V

274 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V

275 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l)

276 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V

277 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ...

278 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ... E = ? V ||

279 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ... E = ? V || E’cell – (0.059/n) log Q =

280 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ... E = ? V || E’cell – (0.059/n) log Q = E’cell – (0.059/n) log [[Fe+3]4[O2]3/[FeO4-2]4[H+]20]

281 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ... E = ? V || E’cell – (0.059/n) log Q = E’cell – (0.059/n) log [[Fe+3]4[O2]3/[FeO4-2][H+]20] = V – (0.059/12) log [[1.0x10-3]4[1.0x10-5]3 /[2.0x10-3]4[6.31x10-6]20

282 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ... E = ? V || E’cell – (0.059/n) log Q = E’cell – (0.059/n) log [[Fe+3]4[O2]3/[FeO4-2][H+]20] = V – (0.059/12) log [[1.0x10-3]4[1.0x10-5]3 /[2.0x10-3]4[6.31x10-6]20 = V – (4.9 x 10-3) log (6.3 x 1087)

283 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ... E = ? V || E’cell – (0.059/n) log Q = E’cell – (0.059/n) log [[Fe+3]4[O2]3/[FeO4-2][H+]20] = V – (0.059/12) log [[1.0x10-3]4[1.0x10-5]3 /[2.0x10-3]4[6.31x10-6]20 = V – (4.9 x 10-3) log (6.3 x 1087) = V – 0.43 V =

284 Electrochemistry Nernst Equation …. Known: @ T = 25 ‘C Unknown:
EQ1: FeO H+1 + 3e > Fe+3 + 4H2O E’ = V E’cell = ? V EQ2: O2+ 4H+1 + 4e > 2 H2O E’ = V [FeO4-2] = 2.0 x 10-3 M [O2] = 1.0 x 10-5 atm [Fe+3] = 1.0 x 10-3 M pH = 5.2 Solution: EQ1 has higher reduction potential ... It wil be reduced ... EQ1 will be oxidized ... EQ1 is multiplied by EQ2 is multiplied by 1st: Calculate E’cell .... 4FeO H e > 4Fe H2O E’ = V 6 H2O ----> 3O2+ 12H e-1 E’ = V 4FeO4-2(aq) + 20H+1(aq) ----> 4Fe+3 + 3O2(g) + 10H2O(l) E’cell = V 2nd: Calculate the E’cell ... E = ? V || E’cell – (0.059/n) log Q = E’cell – (0.059/n) log [[Fe+3]4[O2]3/[FeO4-2][H+]20] = V – (0.059/12) log [[1.0x10-3]4[1.0x10-5]3 /[2.0x10-3]4[6.31x10-6]20 = V – (4.9 x 10-3) log (6.3 x 1087) = V – 0.43 V = 0.54 V

285 Electrochemistry Nernst Equation ….

286 Electrochemistry Nernst Equation Equilibrium ...

287 Electrochemistry Nernst Equation Equilibrium ... E & ∆G = Thus ...

288 Electrochemistry Nernst Equation Equilibrium ... E & ∆G = Thus ... log K = nE’ / @ 25 ‘C

289 Electrochemistry Nernst Equation Equilibrium ... E & ∆G = Thus ... log K = nE’ / @ 25 ‘C

290 Electrochemistry Equilibrium Constants and Cell Potential …


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