AP Chemistry: Chapter 17 Student Notes

Objectives

17.1a: Review Redox

Assign Oxidation Numbers to the following:a. HNO3

b. PbSO4

c. (NH4)2Ce(SO4)3

Balance the following in medium Al (s) + MnO4

- (aq) Al3+ (aq) + Mn2+ (aq)

Balance the following in a basic mediumMg (s) + OCl- (aq) Mg(OH)2 (s) + Cl- (aq)

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17.1a: Review of Redox 17.1: Galvanic Cells 17.2: Standard Reduction Potentials 17.3: Cell Potential and Equilibrium 17.4: The Nernst Equation 17.5--6: Batteries & Corrosion 17.6: Electrolysis

Balance the following Redox Reaction: The big nasty problem

K4Fe(CN)6 + KMnO4 + H2SO4 KHSO4 + Fe2(SO4)3 + MnSO4 + HNO3 +  CO2 +H2O

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17.1: Galvanic Cells

Review of Redox Reactions

Oxidation: _______________________

Reduction: ___________________________

How to make a __________________ _____________________ (gc)

Which is a _____________________

You need to make separate __________________ for each _____________ reaction.

The problem with this cell is …..

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If you put a ______________ ________________ the cell will produce ___________ for a long time.

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Galvanic Cells: Label All parts

What happens when one of the electrodes is not a metal?

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17.2: Standard Reduction Potentials

Half-reaction   E° (V)  

Li+ + e− ⇄ Li(s)  −3.0401

Cs+ + e− ⇄ Cs(s)  −3.026

Rb+ + e− ⇄ Rb(s)  −2.98

K+ + e− ⇄ K(s)  −2.931

Ba2+ + 2 e− ⇄ Ba(s)  −2.912

Sr2+ + 2 e− ⇄ Sr(s)  −2.899

Ca2+ + 2 e− ⇄ Ca(s)  −2.868

Na+ + e− ⇄ Na(s)  −2.71

Mg2+ + 2 e− ⇄ Mg(s)  −2.372

Al(OH)4− + 3 e− ⇄ Al(s) + 4 OH−  −2.33

Al(OH)3(s) + 3 e− ⇄ Al(s) + 3OH−  −2.31

Al3+ + 3 e− ⇄ Al(s)  −1.66

Ti3+ + 3 e− ⇄ Ti(s)  −1.21

Mn2+ + 2 e− ⇄ Mn(s)  −1.185

2 H2O + 2 e− ⇄ H2(g) + 2 OH−  −0.8277

Zn2+ + 2 e− ⇄ Zn(s)  −0.7618

Cr3+ + 3 e− ⇄ Cr(s)  −0.74

PbO(s) + H2O + 2 e− ⇄ Pb(s) + 2 OH−  −0.58

H3PO2(aq) + H+ + e− ⇄ P(white[9]) + 2 H2O  −0.508

H3PO3(aq) + 2 H+ + 2 e− ⇄ H3PO2(aq) + H2O  −0.499

H3PO3(aq) + 3 H+ + 3 e− ⇄ P(red)[9] + 3H2O  −0.454

Fe2+ + 2 e− ⇄ Fe(s)  −0.44

2 CO2(g) + 2 H+ + 2 e− ⇄ HOOCCOOH(aq)  −0.43

Cr3+ + e− ⇄ Cr2+  −0.42

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Cd2+ + 2 e− ⇄ Cd(s)  −0.40

Cu2O(s) + H2O + 2 e− ⇄ 2 Cu(s) + 2 OH−  −0.360

PbSO4(s) + 2 e− ⇄ Pb(s) + SO42−  −0.3588

PbSO4(s) + 2 e− ⇄ Pb(Hg) + SO42−  −0.3505

Co2+ + 2 e− ⇄ Co(s)  −0.28

H3PO4(aq) + 2 H+ + 2 e− ⇄ H3PO3(aq) + H2O  −0.276

Ni2+ + 2 e− ⇄ Ni(s)  −0.25

MoO2(s) + 4 H+ + 4 e− ⇄ Mo(s) + 2 H2O  −0.15

Si(s) + 4 H+ + 4 e− ⇄ SiH4(g)  −0.14

Sn2+ + 2 e− ⇄ Sn(s)  −0.13

Pb2+ + 2 e− ⇄ Pb(s)  −0.13

CO2(g) + 2 H+ + 2 e− ⇄ CO(g) + H2O  −0.11

HCOOH(aq) + 2 H+ + 2 e− ⇄ HCHO(aq) + H2O

 −0.03

2 H+ + 2 e− ⇄ H2(g)    0.0000

S4O62− + 2 e− ⇄ 2 S2O3

2−  +0.08

HgO(s) + H2O + 2 e− ⇄ Hg(l) + 2 OH−  +0.0977

C(s) + 4 H+ + 4 e− ⇄ CH4(g)  +0.13

Sn4+ + 2 e− ⇄ Sn2+  +0.15

Cu2+ + e− ⇄ Cu+  +0.159

HSO4− + 3 H+ + 2 e− ⇄ SO2(aq) + 2 H2O  +0.16

SO42− + 4 H+ + 2 e− ⇄ SO2(aq) + 2 H2O  +0.17

TiO2+ + 2 H+ + e− ⇄ Ti3+ + H2O  +0.19

H3AsO3(aq) + 3 H+ + 3 e− ⇄ As(s) + 3 H2O  +0.24

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UO2+ + 4 H+ + e− ⇄ U4+ + 2 H2O  +0.273

Bi3+ + 3 e− ⇄ Bi(s)  +0.32

VO2+ + 2 H+ + e− ⇄ V3+ + H2O  +0.34

Cu2+ + 2 e− ⇄ Cu(s)  +0.340

O2(g) + 2 H2O + 4 e− ⇄ 4 OH−(aq)  +0.40

CH3OH(aq) + 2 H+ + 2 e− ⇄ CH4(g) + H2O  +0.50

Cu+ + e− ⇄ Cu(s)  +0.520 CO(g) + 2 H+ + 2 e− ⇄ C(s) + H2O  +0.52I2(s) + 2 e− ⇄ 2 I−  +0.54 H3AsO4(aq) + 2 H+ + 2 e− ⇄ H3AsO3(aq) + H2O  +0.56MnO4

− + 2 H2O + 3 e− ⇄ MnO2(s) + 4 OH−  +0.59O2(g) + 2 H+ + 2 e− ⇄ H2O2(aq)  +0.70PtCl4

2− + 2 e− ⇄ Pt(s) + 4 Cl−  +0.758Fe3+ + e− ⇄ Fe2+  +0.77Ag+ + e− ⇄ Ag(s)  +0.7996Hg2

2+ + 2 e− ⇄ 2 Hg(l)  +0.80Hg2+ + 2 e− ⇄ Hg(l)  +0.85MnO4

− + H+ + e− ⇄ HMnO4−  +0.90

2 Hg2+ + 2 e− ⇄ Hg22+  +0.91

Pd 2+ + 2 e− ⇄ Pd(s)  +0.915 [AuCl4]− + 3 e− ⇄ Au(s) + 4 Cl−  +0.93MnO2(s) + 4 H+ + e− ⇄ Mn3+ + 2 H2O  +0.95 [AuBr2]− + e− ⇄ Au(s) + 2 Br−  +0.96

Br2(l) + 2 e− ⇄ 2 Br−  +1.066Br2(aq) + 2 e− ⇄ 2 Br−  +1.0873 IO3

− + 5 H+ + 4 e− ⇄ HIO(aq) + 2 H2O  +1.13 HSeO4

− + 3 H+ + 2 e− ⇄ H2SeO3(aq) + H2O  +1.15Ag2O(s) + 2 H+ + 2 e− ⇄ 2 Ag(s) + H2O  +1.17ClO3

− + 2 H+ + e− ⇄ ClO2(g) + H2O  +1.18Pt 2+ + 2 e− ⇄ Pt(s)  +1.188ClO2(g) + H+ + e− ⇄ HClO2(aq)  +1.19 2 IO3

− + 12 H+ + 10 e− ⇄ I2(s) + 6 H2O  +1.20ClO4

− + 2 H+ + 2 e− ⇄ ClO3− + H2O  +1.20

O2(g) + 4 H+ + 4 e− ⇄ 2 H2O  +1.23MnO2(s) + 4 H+ + 2 e− ⇄ Mn2+ + 2H2O  +1.23Cl2(g) + 2 e− ⇄ 2 Cl−  +1.36Cr2O7

− − + 14 H+ + 6 e− ⇄ 2 Cr3+ + 7 H2O  +1.33CoO2(s) + 4 H+ + e− ⇄ Co3+ + 2 H2O  +1.42 2 NH3OH + + H+ + 2 e− ⇄ N2H5

+ + 2 H2O  +1.42 2 HIO(aq) + 2 H+ + 2 e− ⇄ I2(s) + 2 H2O  +1.44Ce4+ + e− ⇄ Ce3+  +1.44BrO3

− + 5 H+ + 4 e− ⇄ HBrO(aq) + 2 H2O  +1.45 β-PbO2(s) + 4 H+ + 2 e− ⇄ Pb2+ + 2 H2O  +1.460 α-PbO2(s) + 4 H+ + 2 e− ⇄ Pb2+ + 2 H2O  +1.468 2 BrO3

− + 12 H+ + 10 e− ⇄ Br2(l) + 6 H2O  +1.48 2ClO3

− + 12 H+ + 10 e− ⇄ Cl2(g) + 6 H2O  +1.49MnO4

− + 8 H+ + 5 e− ⇄ Mn2+ + 4 H2O  +1.51 HO2

• + H+ + e− ⇄ H2O2(aq)  +1.51Au3+ + 3 e− ⇄ Au(s)  +1.52NiO2(s) + 4 H+ + 2 e− ⇄ Ni2+ + 2 OH−  +1.59 2 HClO(aq) + 2 H+ + 2 e− ⇄ Cl2(g) + 2 H2O  +1.63Ag2O3(s) + 6 H+ + 4 e− ⇄ 2 Ag+ + 3 H2O  +1.67 HClO2(aq) + 2 H+ + 2 e− ⇄ HClO(aq) + H2O  +1.67Pb4+ + 2 e− ⇄ Pb2+  +1.69MnO4

− + 4 H+ + 3 e− ⇄ MnO2(s) + 2 H2O  +1.70 H2O2(aq) + 2 H+ + 2 e− ⇄ 2 H2O  +1.78

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AgO(s) + 2 H+ + e− ⇄ Ag+ + H2O  +1.77Co3+ + e− ⇄ Co2+  +1.82Au+ + e− ⇄ Au(s)  +1.83BrO4

− + 2 H+ + 2 e− ⇄ BrO3− + H2O  +1.85

Ag2+ + e− ⇄ Ag+  +1.98S2O8

2− + 2 e− ⇄ 2 SO42−  +2.010

O3(g) + 2 H+ + 2 e− ⇄ O2(g) + H2O  +2.075 HMnO4

− + 3 H+ + 2 e− ⇄ MnO2(s) + 2 H2O  +2.09F2(g) + 2 e− ⇄ 2 F−  +2.87F2(g) + 2 H+ + 2 e− ⇄ 2 HF(aq)  +3.05

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Calculating & Using Electrical Potential

The table above assumes that you have a __________ M solution at ________atm and _________ºC

Example 1: What would be the electrical potential for the reaction:PbO2 + Na Pb2+ + Na+

Fe3+ + Mg Mg2+ + Fe2+

Example 2: Is H2(g) capable of reducing Ag+(aq)

Is H2(g) capable of reducing Ni2+ (aq)

Is Fe2+ (aq) capable of reducing VO2+

Is Fe2+ capable fo reducing Cr3+ (aq)

Example 3: Rank the following from strongest oxidizing agent to weakest oxidizing agent:Ce4+ Ce3+ Fe2+ Fe3+

Mg2+ Mg Ni2+ Sn

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17.3: Cell Potential and Equilibrium∆G=-nFEº

Example: Using the data in table 17.1, calculate ∆Gº for the reaction:Cu2+ (aq) + Fe(s) Cu(s) + Fe2+ (aq)

17.4: The Nernst EquationWhat happens when concentration and temperatures are not standard?Nernst Equation

Sometimes written as:

Assuming 25ºC

Example 1: What is the electrical potential for the following cell with the following concentrations?VO2

+ + Zn Zn2+ + VO2+

[VO2+] = 2.0 M [H+] = 0.50 M

[VO2+] = 1.0 x 10-2 M [Zn2+] = 0.10 M

First: Write the balanced equation: Use the table of reduction potentials

Second: find Eº

Third: Use the Nernst Equation and plug in the concentration values for Q

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Concentration Cells:

17.4-17.5: Batteries and Corrosion

A Galvanic Cell or a series of galvanic cells hooked together.

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Corrosion

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17.7: ElectrolysisThe opposite of a galvanic cell: Pump electricity through a non ___________ reaction.

Comparison of a galvanic cell and an electrolytic cell

Electrolytic Cell ____________________________

Electrolysis __________________________________

Ampere: ___________________________

Faraday ________________________________

The Story of Aluminum

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Example 1: Calculate the amount of time required to produce 1000 g of magnesium metal by electrolysis of molten MgCl2 using a current of 50A.

Example 2:A Cr3+ (aq) solution is electrolyzed, using a current of 7.60 A. What mass of Cr (s) is plated out after 2.00 days?

What amperage is required to plate out 0.250 mol Cr form a Cr3+ solution in a period of 8.00 hours?

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Example 3: What reaction will take place at the cathode and the anode when each of the following is electrolyzed?

a. 1.0 M KF solution

b. 1.0 M CuCl2 solution

c. 1.0 M H2O2 solution containing 1.0 M HCl

10, 122, 299 ---> 162, 5, 122, 60, 60, 188

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AP Style Questions2002

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2000

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