Question 1

Identify the characteristics of a spontaneous reaction.

Accepted Answer

A)  ΔG° cell > 0 
C)  K > 1 
D)  all of the above 
E)  none of the above 
A)  ΔG° cell > 0 
C)  K > 1 
D)  all of the above 
E)  none of the above

Question 2

Describe how water can be a good conductor of current.

Accepted Answer

A)  use pure water 
B)  heat the water 
C)  add salt 
D)  chill the water 
E)  vaporize the water 
A)  use pure water 
B)  heat the water 
C)  add salt 
D)  chill the water 
E)  vaporize the water

Question 3

Sketch a voltaic cell that contains the following half reactions and label all relevant components.
Zn2+(aq)+ 2e⁻ → Zn(s)E°= -0.76 V
Cu2+(aq)+ 2e⁻ → Cu(s)E°= +0.34 V

Accepted Answer

The sketch should be

Question 4

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Al(s)∣ Al3+(aq,0.115 M)   Al3+(aq,3.89 M)∣ Al(s)

Accepted Answer

A)  +1.66 V 
B)  +0.060 V 
C)  0.00 V 
D)  +0.090 V 
E)  +0.030 V 
A)  +1.66 V 
B)  +0.060 V 
C)  0.00 V 
D)  +0.090 V 
E)  +0.030 V

Question 5

What is the balanced equation for the galvanic cell reaction expressed using shorthand notation below? .
Zn(s)∣ Zn2+(aq)∣∣ Cl2(g)∣ Cl-(aq)∣ C(s)

Accepted Answer

A)  Zn(s) + 2 Cl-(aq) → Zn2+(aq) + Cl2(g) 
B)  Zn(s) + Cl2(g) → Zn2+(aq) + 2 Cl-(aq) 
C)  Zn2+(aq) + 2 Cl-(aq) → Zn(s) + Cl2(g) 
D)  Zn2+(aq) + 2 Cl-(aq) → ZnCl2(s) 
A)  Zn(s) + 2 Cl-(aq) → Zn2+(aq) + Cl2(g) 
B)  Zn(s) + Cl2(g) → Zn2+(aq) + 2 Cl-(aq) 
C)  Zn2+(aq) + 2 Cl-(aq) → Zn(s) + Cl2(g) 
D)  Zn2+(aq) + 2 Cl-(aq) → ZnCl2(s)

Question 6

Why,if we multiply a reaction by 2,don't we multiply its E°red by 2?

Accepted Answer

Half-cell potentials (E°_red)are a

Question 7

Which of the following metals will dissolve in nitric acid but not hydrochloric acid?

Accepted Answer

A)  Ca 
B)  Mn 
C)  Cu 
D)  Sn 
E)  Ni 
A)  Ca 
B)  Mn 
C)  Cu 
D)  Sn 
E)  Ni

Question 8

Balance the following reaction in KOH.What are the coefficients in front of H2O and KOH in the balanced reaction and list which side of the equation that H2O and KOH appear?
C3H8O2(aq)+ KMnO4(aq)→ C3H2O4K2(aq)+ MnO2(aq)

Accepted Answer

A)  H2O = 1, KOH = 4, right 
B)  H2O = 4, KOH = 1, left 
C)  H2O = 8, KOH = 2 right 
D)  H2O = 3, KOH = 2, right 
E)  H2O = 4, KOH = 2, left 
A)  H2O = 1, KOH = 4, right 
B)  H2O = 4, KOH = 1, left 
C)  H2O = 8, KOH = 2 right 
D)  H2O = 3, KOH = 2, right 
E)  H2O = 4, KOH = 2, left

Question 9

Determine the cell notation for the redox reaction given below. 3 Cl2(g)+ 2 Fe(s)→ 6 Cl⁻(aq)+ 2 Fe3+(aq)

Accepted Answer

A)  Cl2(g) ∣ Cl⁻(aq) ∣ Pt   Fe(s) ∣ Fe3+(aq) 
B)  Cl⁻(aq) ∣ Cl2(g) ∣ Pt   Fe3+(aq) ∣ Fe(s) 
C)  Fe3+(aq) ∣ Fe(s)   Cl⁻(aq) ∣ Cl2(g) ∣ Pt 
D)  Fe(s) ∣ Cl2(g)   Fe3+(aq) ∣ Cl⁻(aq) ∣ Pt 
E)  Fe(s) ∣ Fe3+(aq)   Cl2(g) ∣ Cl⁻(aq) ∣ Pt 
A)  Cl2(g) ∣ Cl⁻(aq) ∣ Pt   Fe(s) ∣ Fe3+(aq) 
B)  Cl⁻(aq) ∣ Cl2(g) ∣ Pt   Fe3+(aq) ∣ Fe(s) 
C)  Fe3+(aq) ∣ Fe(s)   Cl⁻(aq) ∣ Cl2(g) ∣ Pt 
D)  Fe(s) ∣ Cl2(g)   Fe3+(aq) ∣ Cl⁻(aq) ∣ Pt 
E)  Fe(s) ∣ Fe3+(aq)   Cl2(g) ∣ Cl⁻(aq) ∣ Pt

Question 10

Given that E°red = -0.45 V for Fe2+/Fe at 25°C,find E° and E for the concentration cell expressed using shorthand notation below. Fe(s)∣ Fe2+(1.0 × 10-5 M)∣∣ Fe2+(0.100 M)∣ Fe(s)

Accepted Answer

A)  E° = 0.00 V and E = +0.24 V 
B)  E° = 0.00 V and E = +0.12 V 
C)  E° = -0.45 V and E = -0.21 V 
D)  E° = -0.45 V and E = -0.33 V 
A)  E° = 0.00 V and E = +0.24 V 
B)  E° = 0.00 V and E = +0.12 V 
C)  E° = -0.45 V and E = -0.21 V 
D)  E° = -0.45 V and E = -0.33 V

Question 11

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25°C.(The equation is balanced.) Sn(s)+ 2 Ag⁺(aq)→ Sn2+(aq)+ 2 Ag(s)
Sn2+(aq)+ 2 e⁻ → Sn(s)E° = -0.14 V
Ag⁺(aq)+ e⁻ → Ag(s)E° = +0.80 V

Accepted Answer

A)  +1.74 V 
B)  +0.94 V 
C)  +1.08 V 
D)  -1.08 V 
E)  -1.74 V 
A)  +1.74 V 
B)  +0.94 V 
C)  +1.08 V 
D)  -1.08 V 
E)  -1.74 V

Question 12

What statement is NOT true about standard electrode potentials?

Accepted Answer

A)  E°cell is positive for spontaneous reactions. 
B)  Electrons will flow from more negative electrode to more positive electrode. 
C)  The electrode potential of the standard hydrogen electrode is exactly zero. 
D)  E°cell is the difference in voltage between the anode and the cathode. 
E)  The electrode in any half-cell with a greater tendency to undergo reduction is positively charged relative to the standard hydrogen electrode and therefore has a positive E°. 
A)  E°cell is positive for spontaneous reactions. 
B)  Electrons will flow from more negative electrode to more positive electrode. 
C)  The electrode potential of the standard hydrogen electrode is exactly zero. 
D)  E°cell is the difference in voltage between the anode and the cathode. 
E)  The electrode in any half-cell with a greater tendency to undergo reduction is positively charged relative to the standard hydrogen electrode and therefore has a positive E°.

Question 13

Give an example of an inert electrode.

Accepted Answer

graphite o

Question 14

What is undergoing reduction in the redox reaction represented by the following cell notation?
Cr(s)∣ Cr3+(aq)   I2(g)∣ I⁻(aq)∣ Pt

Accepted Answer

A)  Cr(s) 
B)  Cr3+(aq) 
C)  I2(g) 
D)  I⁻(aq) 
E)  Pt 
A)  Cr(s) 
B)  Cr3+(aq) 
C)  I2(g) 
D)  I⁻(aq) 
E)  Pt

Question 15

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25°C.(The equation is balanced.) Pb(s)+ Br2(l)→ Pb2+(aq)+ 2 Br⁻(aq)
Pb2+(aq)+ 2 e⁻ → Pb(s)E° = -0.13 V
Br2(l)+ 2 e⁻ → 2 Br⁻(aq)E° = +1.07 V

Accepted Answer

A)  +1.20 V 
B)  +0.94 V 
C)  -0.94 V 
D)  -1.20 V 
E)  -0.60 V 
A)  +1.20 V 
B)  +0.94 V 
C)  -0.94 V 
D)  -1.20 V 
E)  -0.60 V

Question 16

Which of the following metals will not dissolve in nitric acid or hydrochloric acid?

Accepted Answer

A)  Pb 
B)  Cu 
C)  Fe 
D)  Ag 
E)  all of the above 
A)  Pb 
B)  Cu 
C)  Fe 
D)  Ag 
E)  all of the above

Question 17

What is the shorthand notation that represents the following galvanic cell reaction?
Ni(s)+ Cu(NO3)2(aq)→ Ni(NO3)2(aq)+ Cu(s)

Accepted Answer

A)  Ni(s) ∣ Ni2+(aq) ∣∣ Cu2+(aq) ∣ Cu(s) 
B)  Cu(s) ∣ Cu2+(aq) ∣∣ Ni2+(aq) ∣ Ni(s) 
C)  Ni(s) ∣ NO3-(aq) ∣∣ NO3-(aq) ∣ Cu(s) 
D)  Cu(s) ∣ Cu(NO3)2(aq) ∣∣ Ni(NO3)2(aq) ∣ Ni(s) 
A)  Ni(s) ∣ Ni2+(aq) ∣∣ Cu2+(aq) ∣ Cu(s) 
B)  Cu(s) ∣ Cu2+(aq) ∣∣ Ni2+(aq) ∣ Ni(s) 
C)  Ni(s) ∣ NO3-(aq) ∣∣ NO3-(aq) ∣ Cu(s) 
D)  Cu(s) ∣ Cu(NO3)2(aq) ∣∣ Ni(NO3)2(aq) ∣ Ni(s)

Question 18

What element is being reduced in the following redox reaction?
H2O2(l)+ ClO2(aq)→ ClO2⁻(aq)+ O2(g)

Accepted Answer

A)  H 
B)  O 
C)  Cl 
D)  N 
E)  C 
A)  H 
B)  O 
C)  Cl 
D)  N 
E)  C

Question 19

How many electrons are transferred in the following reaction? (The reaction is unbalanced.)
Mg2+(aq)+ Li(s)→ Mg(s)+ Li+(aq)

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  6 
A)  1 
B)  2 
C)  3 
D)  4 
E)  6

Question 20

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of Al and Br2 in the balanced reaction?
Al(s)+ Br2(g)→ Al3+(aq)+ Br-(aq)

Accepted Answer

A)  Al = 2, Br2 = 3 
B)  Al = 2, Br2 = 6 
C)  Al = 1, Br2 = 1 
D)  Al = 2, Br2 = 1 
E)  Al = 3, Br2 = 2 
A)  Al = 2, Br2 = 3 
B)  Al = 2, Br2 = 6 
C)  Al = 1, Br2 = 1 
D)  Al = 2, Br2 = 1 
E)  Al = 3, Br2 = 2

Exam 20: Electrochemistry

Identify the characteristics of a spontaneous reaction.

Describe how water can be a good conductor of current.

Sketch a voltaic cell that contains the following half reactions and label all relevant components. Zn2+(aq)+ 2e⁻ → Zn(s)E°= -0.76 V Cu2+(aq)+ 2e⁻ → Cu(s)E°= +0.34 V

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Al(s)∣ Al3+(aq,0.115 M) Al3+(aq,3.89 M)∣ Al(s)

What is the balanced equation for the galvanic cell reaction expressed using shorthand notation below? . Zn(s)∣ Zn2+(aq)∣∣ Cl2(g)∣ Cl-(aq)∣ C(s)

Why,if we multiply a reaction by 2,don't we multiply its E°red by 2?

Which of the following metals will dissolve in nitric acid but not hydrochloric acid?

Balance the following reaction in KOH.What are the coefficients in front of H2O and KOH in the balanced reaction and list which side of the equation that H2O and KOH appear? C3H8O2(aq)+ KMnO4(aq)→ C3H2O4K2(aq)+ MnO2(aq)

Determine the cell notation for the redox reaction given below. 3 Cl2(g)+ 2 Fe(s)→ 6 Cl⁻(aq)+ 2 Fe3+(aq)

Given that E°red = -0.45 V for Fe2+/Fe at 25°C,find E° and E for the concentration cell expressed using shorthand notation below. Fe(s)∣ Fe2+(1.0 × 10-5 M)∣∣ Fe2+(0.100 M)∣ Fe(s)

What statement is NOT true about standard electrode potentials?

Give an example of an inert electrode.

What is undergoing reduction in the redox reaction represented by the following cell notation? Cr(s)∣ Cr3+(aq) I2(g)∣ I⁻(aq)∣ Pt

Which of the following metals will not dissolve in nitric acid or hydrochloric acid?

What is the shorthand notation that represents the following galvanic cell reaction? Ni(s)+ Cu(NO3)2(aq)→ Ni(NO3)2(aq)+ Cu(s)

What element is being reduced in the following redox reaction? H2O2(l)+ ClO2(aq)→ ClO2⁻(aq)+ O2(g)

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Mg2+(aq)+ Li(s)→ Mg(s)+ Li+(aq)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of Al and Br2 in the balanced reaction? Al(s)+ Br2(g)→ Al3+(aq)+ Br-(aq)

Essentials: Units, Measurements, and Problem Solving

Atoms

The Quantum Mechanical Model of the Atom

Periodic Properties of the Elements

Molecules and Compounds

Chemical Bonding I

Chemical Bonding Ii

Chemical Reactions and Chemical Quantities

Introduction to Solutions and Aqueous Reactions

Thermochemistry

Gases

Liquids, Solids, and Intermolecular Forces

Crystalline Solids and Modern Materials

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Free Energy and Thermodynamics

Radioactivity and Nuclear Chemistry

Organic Chemistry

Transition Metals and Coordination Compounds

Filters

Sketch a voltaic cell that contains the following half reactions and label all relevant components. Zn²⁺(aq)+ 2e⁻ → Zn(s)E°= -0.76 V Cu²⁺(aq)+ 2e⁻ → Cu(s)E°= +0.34 V

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Al(s)∣ Al³⁺(aq,0.115 M) Al³⁺(aq,3.89 M)∣ Al(s)

What is the balanced equation for the galvanic cell reaction expressed using shorthand notation below? . Zn(s)∣ Zn²⁺(aq)∣∣ Cl₂(g)∣ Cl^-(aq)∣ C(s)

Why,if we multiply a reaction by 2,don't we multiply its E°_red by 2?

Balance the following reaction in KOH.What are the coefficients in front of H₂O and KOH in the balanced reaction and list which side of the equation that H₂O and KOH appear? C₃H₈O₂(aq)+ KMnO₄(aq)→ C₃H₂O₄K₂(aq)+ MnO₂(aq)

Determine the cell notation for the redox reaction given below. 3 Cl₂(g)+ 2 Fe(s)→ 6 Cl⁻(aq)+ 2 Fe³⁺(aq)

Given that E°_red = -0.45 V for Fe²⁺/Fe at 25°C,find E° and E for the concentration cell expressed using shorthand notation below. Fe(s)∣ Fe²⁺(1.0 × 10^-5 M)∣∣ Fe²⁺(0.100 M)∣ Fe(s)

What is undergoing reduction in the redox reaction represented by the following cell notation? Cr(s)∣ Cr³⁺(aq) I₂(g)∣ I⁻(aq)∣ Pt

What is the shorthand notation that represents the following galvanic cell reaction? Ni(s)+ Cu(NO₃)₂(aq)→ Ni(NO₃)₂(aq)+ Cu(s)

What element is being reduced in the following redox reaction? H₂O₂(l)+ ClO₂(aq)→ ClO₂⁻(aq)+ O₂(g)

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Mg²⁺(aq)+ Li(s)→ Mg(s)+ Li⁺(aq)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of Aland Br₂ in the balanced reaction? Al(s)+ Br₂(g)→ Al³⁺(aq)+ Br^-(aq)