CHM 2046C Name: ________________
Module 14 Paper
and Pencil Homework Packet
Possible |
Actual |
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F. The Nernst Equation Calculation Section 17.6 |
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G. Electrochemical Determination of pH Section 17.1 |
5 |
Answers |
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H. Standard Cell
Potentials & EquilibriumConstants Section 17.8 |
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I. Batteries, Fuel
Cells, Electrolysis Section 17.9, 17.11, 17.12 |
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Module Fourteen
Total: |
45 |
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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
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