CHM 2046C Name: ________________

Module 14 Paper and Pencil Homework Packet

Module Fourteen: Electrochemistry Chapter 17

Possible

Actual

Module Fourteen: Electrochemistry Chapter 17

C. Galvanic Cells Section 17.1

5

Answers

D. Cell Notation Section 17.2

5

Answers

E. Cell Potentials and Free Energy Section 17.3

5

Answers

F. The Nernst Equation Calculation Section 17.6

5

Answers

G. Electrochemical Determination of pH Section 17.1

5

Answers

H. Standard Cell Potentials & EquilibriumConstants Section 17.8

5

Answers

I. Batteries, Fuel Cells, Electrolysis Section 17.9, 17.11, 17.12

5

Answers

J. Discussion/Review Questions - Chapter 17

5

Answers

K. Key Terms - Chapter 17

5

Answers

Module Fourteen Total:

45

 

 

Part C: Cell Basics 5 points

 

Match the following:

 

____1. Anode

 

____2. Cathode

 

____3. Direction of Electron Flow

 

____4. Anion Flow

 

____5. Cation Flow

 

____6. Negative Charged

 

____7. Positive Charged (Circle One)

 

____8. Site of Oxidation

 

____9. Site of Reduction

 

_______10. Salt Bridge: CuSO4, ZnSO4 or Na2SO4 (or Circle One)

 

Reaction at Anode: ________________________________

 

Reaction at Cathode: _________________________________

 

Page 2: Module 14 Paper and Pencil Homework Packet

 

Part D: Shorthand Notation for Galvanic Cells 5 points

 

For the following Galvanic Cell:

 

1. Write the Shorthand notation for the above voltaic cell:

 

 

 

 

 

2. Write a balanced equation for the cell reaction:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 3: Module 14 Paper and Pencil Homework Packet

 

Part E: Calculating Standard Cell Potentials 5 points

 

 

1. The standard potential for the following galvanic cell is 0.92 V:

Al(s) | Al3+ (aq) || Cr3+ (aq) | Cr (s)

 

Show the Anode Reaction, Cathode Reaction, Overall Cell Reaction then using the above table look up the standard reduction potential for Al3+ /Al(s) half cell and calculate the standard reduction potential for the Cr3+/Cr half cell:

 

Anode Reaction: Eo =

 

Cathode Reaction: Eo =

--------------------------------------------------------------------

Overall Reaction: Eo =

 

2. Using the above table, calculate overall cell potential for the following cell:

Pt(s) | H2 (1 atm) | H1+ (1 M) || Cu2+ (1 M) | Cu (s)

 

Page 4: Module 14 Paper and Pencil Homework Packet

 

Part F: Calculating Cell Potentials using the Nernst Equation

5 points

 

Nernst Equation:

E = Eo RT/nF [ln Q] or E = Eo - 2.303RT/nF [log Q]

 

Or E = Eo 0.0592 V/n [log Q] in volts at 25oC

 

Worked Example 17.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 5: Module 14 Paper and Pencil Homework Packet

 

Part G: Electrochemical Determination of pH 5 points

 

Nernst Equation:

E = Eo RT/nF [ln Q] or E = Eo - 2.303RT/nF [log Q]

 

Or E = Eo 0.0592 V/n [log Q] in volts at 25oC

 

Standard Cell Potential and the Equilibrium Constant:

Eo =0.0593 V/n [log K] in volts at 25oC

 

 

Worked Example 17.8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 6: Module 14 Paper and Pencil Homework Packet

 

Part H: Standard Cell Potentials and Equilibrium Constants

5 points

 

Nernst Equation:

E = Eo RT/nF [ln Q] or E = Eo - 2.303RT/nF [log Q]

 

Or E = Eo 0.0592 V/n [log Q] in volts at 25oC

 

Standard Cell Potential and the Equilibrium Constant:

Eo =0.0593 V/n [log K] in volts at 25oC

 

R = 8.31451 J / K∙mol F = Faraday Constant = 9.6485309 x 104 J/V∙mol

 

Worked Example 17.9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 7: Module 14 Paper and Pencil Homework Packet

Part I: Batteries, Fuel Cell, Electrolysis 5 points

Dry Cell Battery Mercury Battery

Match the following:

Dry Cell Mercury Cell

____1. Cathode ______11. Cathode

 

____2. Anode ______12. Anode

 

____3. Zinc Can ______13. Outer Steel Case

 

____4. Carbon Rod ______14. Steel Cover Top

 

____5. Porous Separator ______15. Tin-Plated Inner Top

 

____6. Wax seal ______16. Sealing and Insulated

Gasket

____7. Steel Cover ______17. Zn

 

____8. Sand Cushion ______18. KOH saturated with

ZnO in absorbent Material (electrolyte)

____9. NH4Cl, ZnCl2, MnO2 paste ______19. HgO mixed with

Graphite

____10. Insulating Washer ______20. Barrier

 

Reaction at Anode: ______________ _________________

 

Reaction at Cathode: ______________ _________________

Page 8: Module 14 Paper and Pencil Homework Packet

Part J: Chapter 17 Discussion Questions 5 points

 

1. Which electrode is the anode and which electrode is the cathode in an electrochemical cell?

 

 

 

 

 

 

 

2. What is a salt bridge? Why is such a device necessary?

 

 

 

 

 

 

3. What is the difference between a primary cell and a secondary cell?

 

 

 

 

 

4. What is the relationship between charge, potential, and energy?

 

 

 

 

 

 

 

5. What is the standard electrode? What is a standard electrode-reduction potential? What is its symbol?

 

 

 

 

 

 

 

 

Page 9: Module 14 Paper and Pencil Homework Packet

Part K: Chapter 17 Key Terms 10 points

 

1. ______________ the electrode at which oxidation takes place

 

2. ______________ the electrode at which reduction takes place

 

3. ______________ a technique for protecting a metal from corrosion by converting it to a second metal that is more easily oxidized

 

4. ______________ same as electromotive force

 

5. ______________ the oxidative deterioration of a metal, such as the conversion of iron to rust

 

6. ______________ a devise for interconverting chemical and electrical energy

 

7.. ______________ the area of chemistry concerned with the interconversion of chemical and electrical energy

 

8. ______________ a substance that dissolves in water to produce ions

 

9. ______________ the process of using an electric current to bring about chemical change

 

10. ______________ the electrical potential that pushes electrons away from the anode and pulls them toward the cathode

 

11. ______________ the coating of one metal on the surface of another using electrolysis

12. ______________ the purification of a metal by means of electrolysis

 

13. ______________ the elctric charge on 1 mol of electrons

 

14. ______________ a galvanic cell in which one of the reactants is a traditional fuel such as methane or hydrogen

 

15. ______________ An electrochemical cell in which a spontaneous chemical reaction generates an electric current

 

16. ______________ a process for protecting steel from corrosion by coating it with zinc

 

17. ______________ The oxidation or reduction part of a redox reaction

 

Page 10: Module 14 Paper and Pencil Homework Packet

Park K Continued

 

18. ______________ the commercial method for protecting aluminum by electrolysis of a molten mixture of aluminum oxide and cryolite

 

19. ______________ An equation for calculating cell potentials under non-standard state conditions

 

20. ______________ An additional voltage required above the calculated for an electrolysis reaction

 

21. ______________ A tube that contains a gel permeated with a solution of an inert electrolyte connecting the two sides of an electrochemical cell.

 

22. ______________ The cell potential when both reactants and products are in their saturated states

 

23. ______________ same as standard reduction potential

 

24. ______________ A reference half cell consisting of a platinum electrode in contact with H2 gas and aqueous H1+ ions at standard state conditions

 

25. ______________ The standard potential for a reduction half cell