Question 1

How many coulombs would be required to electroplate 35.0 grams of chromium by passing an electrical current through a solution containing CrCl3?

Accepted Answer

A) 6.50 × 104 C 
B) 2.16 × 104 C 
C) 6.40 × 104 C 
D) 1.95 × 105 C 
E) 1.01 × 107 C 
A) 6.50 × 104 C 
B) 2.16 × 104 C 
C) 6.40 × 104 C 
D) 1.95 × 105 C 
E) 1.01 × 107 C

Question 2

How many grams of copper are deposited on the cathode of an electrolytic cell if an electric current of 2.00 A is passed through a solution of CuSO4 for a period of 19.0 min?

Accepted Answer

Question 3

The half-cell reaction for the oxidation of H2O(l)to O2(g)is given below. 2H2O(l)$\rarr$ O2(g)+ 4H+(aq)+ 4e-
 Which choice lists all of the following species that can oxidize H2O to O2(g)under standard-state conditions?
MnO4-(aq), Cl2(g), Pb2+(aq), Cl- (aq), Ag+(aq)

Accepted Answer

A) Cl-(aq)only 
B) Cl2(g)only 
C) Pb2+(aq)and Ag+(aq) 
D) Cl-(aq)and MnO4-(aq) 
E) MnO4-(aq)and Cl2(g) 
A) Cl-(aq)only 
B) Cl2(g)only 
C) Pb2+(aq)and Ag+(aq) 
D) Cl-(aq)and MnO4-(aq) 
E) MnO4-(aq)and Cl2(g)

Question 4

Complete and balance the following redox equation.The sum of the smallest whole-number coefficients is MnO4- + H+ + Br- $\rarr$ Mn2+ + Br2 + H2O (acidic solution)

Accepted Answer

A) 6 
B) 17 
C) 21 
D) 29 
E) 43 
A) 6 
B) 17 
C) 21 
D) 29 
E) 43

Question 5

In an electrolytic cell, electrical energy is used to cause a chemical reaction to occur that would otherwise be nonspontaneous.

Accepted Answer

A) True 
 B)False

Question 6

Determine the equilibrium constant for the following reaction at 298 K.
2Fe3+(aq)+ H2O2(aq)    
2H+(aq)+ O2(g)+ 2Fe2+(aq).

Accepted Answer

Question 7

For the electrochemical cell Ni(s)| Ni2+(1 M)|| H+(1 M)| H2(1 atm)| Pt(s), which one of the following changes will cause a decrease in the cell voltage?

Accepted Answer

A) Increase the pressure of H2 to 2.0 atm . 
B) Decrease the mass of the nickel electrode. 
C) Lower the pH of the cell electrolyte. 
D) Decrease the concentration of Ni2+ ion. 
E) None of the above. 
A) Increase the pressure of H2 to 2.0 atm . 
B) Decrease the mass of the nickel electrode. 
C) Lower the pH of the cell electrolyte. 
D) Decrease the concentration of Ni2+ ion. 
E) None of the above.

Question 8

Which one of the following reactions must be carried out in an electrolytic cell rather than in a galvanic cell?

Accepted Answer

A) 3Ni2+(aq)+ 2Cr(s)$\rarr$3Ni(s)+ 2Cr3+(aq) 
B) 2Ag+(aq)+ Pb(s)$\rarr$ 2Ag(s)+ Pb2+(aq) 
C) Br2(l)+ 2Cu+(aq)$\rarr$ 2Br-(aq)+ Cu2+(aq) 
D) Cr3+(aq)+ 3Ag(s)$\rarr$Cr + 3Ag+(aq) 
E) 2Fe3+(aq)+ Sn(s)$\rarr$2Fe2+(aq)+ Sn2+(aq) 
A) 3Ni2+(aq)+ 2Cr(s)$\rarr$3Ni(s)+ 2Cr3+(aq) 
B) 2Ag+(aq)+ Pb(s)$\rarr$ 2Ag(s)+ Pb2+(aq) 
C) Br2(l)+ 2Cu+(aq)$\rarr$ 2Br-(aq)+ Cu2+(aq) 
D) Cr3+(aq)+ 3Ag(s)$\rarr$Cr + 3Ag+(aq) 
E) 2Fe3+(aq)+ Sn(s)$\rarr$2Fe2+(aq)+ Sn2+(aq)

Question 9

Consider the following standard reduction potentials in acid solution:   The strongest reducing agent among those shown above is

Accepted Answer

A) Fe3+. 
B) Fe2+. 
C) Br-. 
D) Al3+. 
E) Al. 
A) Fe3+. 
B) Fe2+. 
C) Br-. 
D) Al3+. 
E) Al.

Question 10

Complete and balance the following redox equation.What is the coefficient of H2S when the equation is balanced using the set of smallest whole-number coefficients? H2S + MnO4- $\rarr$ Mn2+ + SO42- (acidic solution)

Accepted Answer

A) 1 
B) 2 
C) 4 
D) 5 
E) None of these. 
A) 1 
B) 2 
C) 4 
D) 5 
E) None of these.

Question 11

Given the following cell diagram, Al(s)| Al3+(aq)|| Cd2+(aq)| Cd (s)
What is the balanced overall (net)cell reaction?

Accepted Answer

A) Al(s)+ Cd2+(aq)$\rarr$Al3+(aq)+ Cd (s) 
B) Al3+(aq)+ Cd (s)$\rarr$ Al(s)+ Cd2+(aq) 
C) 2Al(s)+ 3Cd2+(aq)$\rarr$2Al3+(aq)+ 3Cd (s) 
D) 2Al3+(aq)+ 3Cd (s)$\rarr$2Al(s)+ 3Cd2+(aq) 
E) 3Al3+(aq)+ 2Cd (s)$\rarr$3Al(s)+ 2Cd2+(aq) 
A) Al(s)+ Cd2+(aq)$\rarr$Al3+(aq)+ Cd (s) 
B) Al3+(aq)+ Cd (s)$\rarr$ Al(s)+ Cd2+(aq) 
C) 2Al(s)+ 3Cd2+(aq)$\rarr$2Al3+(aq)+ 3Cd (s) 
D) 2Al3+(aq)+ 3Cd (s)$\rarr$2Al(s)+ 3Cd2+(aq) 
E) 3Al3+(aq)+ 2Cd (s)$\rarr$3Al(s)+ 2Cd2+(aq)

Question 12

Which of the following would be considered a fuel cell?

Accepted Answer

A) C3H8(g)+ 5O2(g)$\rarr$ 3CO2(g)+ 4H2O(l) 
B) Pb(s)+ PbO2(s)+ 4H+(aq)+ 2SO42-(aq)$\rarr$ 2PbSO4(s)+ 2H2O(l) 
C) Zn(s)+ 2NH4+(aq)+ 2MnO2(s)$\rarr$Zn2+(aq)+ 2NH3(aq)+ H2O(l)+ Mn2O3(s) 
D) Zn(Hg)+ HgO(s)$\rarr$ ZnO(s)+ Hg(l) 
E) 2Fe(s)+ O2(g)+ 4H+(aq)$\rarr$ 2Fe2+(aq)+ 2H2O(l) 
A) C3H8(g)+ 5O2(g)$\rarr$ 3CO2(g)+ 4H2O(l) 
B) Pb(s)+ PbO2(s)+ 4H+(aq)+ 2SO42-(aq)$\rarr$ 2PbSO4(s)+ 2H2O(l) 
C) Zn(s)+ 2NH4+(aq)+ 2MnO2(s)$\rarr$Zn2+(aq)+ 2NH3(aq)+ H2O(l)+ Mn2O3(s) 
D) Zn(Hg)+ HgO(s)$\rarr$ ZnO(s)+ Hg(l) 
E) 2Fe(s)+ O2(g)+ 4H+(aq)$\rarr$ 2Fe2+(aq)+ 2H2O(l)

Question 13

Complete and balance the following redox equation using the smallest whole-number coefficients.What is the coefficient of Sn in the balanced equation? 
Sn + HNO3 $\rarr$ SnO2 + NO2 + H2O (acidic solution)

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 14

For the reaction Ni2+(aq)+ 2Fe2+(aq)$\rarr$Ni(s)+ 2Fe3+(aq), the standard cell potential E°cell is

Accepted Answer

A) +2.81 V. 
B) +1.02 V. 
C) +0.52 V. 
D) -1.02 V. 
E) -2.81 V. 
A) +2.81 V. 
B) +1.02 V. 
C) +0.52 V. 
D) -1.02 V. 
E) -2.81 V.

Question 15

Calculate the cell voltage for the following reaction: Cu2+ (0.010 M)+ H2(1 atm)$\rarr$ Cu(s)+ 2H+( pH = 7.0)

Accepted Answer

A) 0.19 V 
B) -0.01 V 
C) 0.34 V 
D) 0.69 V 
E) 0.49 V 
A) 0.19 V 
B) -0.01 V 
C) 0.34 V 
D) 0.69 V 
E) 0.49 V

Question 16

Write the balanced overall redox equation for the following cell diagram:
Cr(s)| Cr3+(aq)|| Sn4+(aq),Sn2+(aq)| Pt(s)

Accepted Answer

2Cr(s)+ 3S

Question 17

Consider the following standard reduction potentials in acid solution:   The weakest reducing agent listed above is

Accepted Answer

A) Cr3+. 
B) Cr. 
C) Mn2+. 
D) Co. 
E) MnO4-. 
A) Cr3+. 
B) Cr. 
C) Mn2+. 
D) Co. 
E) MnO4-.

Question 18

Many different ways have been proposed to make batteries.One cell is set up with copper and lead electrodes in contact with CuSO4(aq)and Pb(NO3)2 (aq), respectively.If the Pb2+ and Cu2+ concentrations are each 1.0 M, what is the overall cell potential?

Accepted Answer

Question 19

A battery is constructed by placing copper and lead electrodes in contact with 1.0 molar CuSO4(aq)and Pb(NO3)2 (aq)solutions, respectively.If sulfuric acid is then added to the Pb(NO3)2 solution, thereby forming a precipitate of PbSO4, what will happen to the cell potential?

Accepted Answer

The cell p

Question 20

The half-reaction that should occur at the anode during electrolysis of an aqueous potassium bromide solution is

Accepted Answer

A) Br2 + 2e- $\rarr$ 2Br-. 
B) Na $\rarr$ Na+ + e-. 
C) Na+ + e- $\rarr$ Na. 
D) 2Br- $\rarr$Br2 + 2e-. 
E) 2H2O $\rarr$ O2 + 4H+ + 4e-. 
A) Br2 + 2e- $\rarr$ 2Br-. 
B) Na $\rarr$ Na+ + e-. 
C) Na+ + e- $\rarr$ Na. 
D) 2Br- $\rarr$Br2 + 2e-. 
E) 2H2O $\rarr$ O2 + 4H+ + 4e-.

Exam 18: Electrochemistry

How many coulombs would be required to electroplate 35.0 grams of chromium by passing an electrical current through a solution containing CrCl3?

How many grams of copper are deposited on the cathode of an electrolytic cell if an electric current of 2.00 A is passed through a solution of CuSO4 for a period of 19.0 min?

The half-cell reaction for the oxidation of H2O(l)to O2(g)is given below. 2H2O(l) →\rarr→ O2(g)+ 4H+(aq)+ 4e- Which choice lists all of the following species that can oxidize H2O to O2(g)under standard-state conditions? MnO4-(aq), Cl2(g), Pb2+(aq), Cl- (aq), Ag+(aq)

Complete and balance the following redox equation.The sum of the smallest whole-number coefficients is MnO4- + H+ + Br- →\rarr→ Mn2+ + Br2 + H2O (acidic solution)

In an electrolytic cell, electrical energy is used to cause a chemical reaction to occur that would otherwise be nonspontaneous.

Determine the equilibrium constant for the following reaction at 298 K. 2Fe3+(aq)+ H2O2(aq) 2H+(aq)+ O2(g)+ 2Fe2+(aq).

For the electrochemical cell Ni(s)| Ni2+(1 M)|| H+(1 M)| H2(1 atm)| Pt(s), which one of the following changes will cause a decrease in the cell voltage?

Which one of the following reactions must be carried out in an electrolytic cell rather than in a galvanic cell?

Consider the following standard reduction potentials in acid solution: The strongest reducing agent among those shown above is

Complete and balance the following redox equation.What is the coefficient of H2S when the equation is balanced using the set of smallest whole-number coefficients? H2S + MnO4- →\rarr→ Mn2+ + SO42- (acidic solution)

Given the following cell diagram, Al(s)| Al3+(aq)|| Cd2+(aq)| Cd (s) What is the balanced overall (net)cell reaction?

Which of the following would be considered a fuel cell?

Complete and balance the following redox equation using the smallest whole-number coefficients.What is the coefficient of Sn in the balanced equation? Sn + HNO3 →\rarr→ SnO2 + NO2 + H2O (acidic solution)

For the reaction Ni2+(aq)+ 2Fe2+(aq) →\rarr→ Ni(s)+ 2Fe3+(aq), the standard cell potential E°cell is

Calculate the cell voltage for the following reaction: Cu2+ (0.010 M)+ H2(1 atm) →\rarr→ Cu(s)+ 2H+( pH = 7.0)

Write the balanced overall redox equation for the following cell diagram: Cr(s)| Cr3+(aq)|| Sn4+(aq),Sn2+(aq)| Pt(s)

Consider the following standard reduction potentials in acid solution: The weakest reducing agent listed above is

Many different ways have been proposed to make batteries.One cell is set up with copper and lead electrodes in contact with CuSO4(aq)and Pb(NO3)2 (aq), respectively.If the Pb2+ and Cu2+ concentrations are each 1.0 M, what is the overall cell potential?

A battery is constructed by placing copper and lead electrodes in contact with 1.0 molar CuSO4(aq)and Pb(NO3)2 (aq)solutions, respectively.If sulfuric acid is then added to the Pb(NO3)2 solution, thereby forming a precipitate of PbSO4, what will happen to the cell potential?

The half-reaction that should occur at the anode during electrolysis of an aqueous potassium bromide solution is

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How many coulombs would be required to electroplate 35.0 grams of chromium by passing an electrical current through a solution containing CrCl₃?

How many grams of copper are deposited on the cathode of an electrolytic cell if an electric current of 2.00 A is passed through a solution of CuSO₄ for a period of 19.0 min?

The half-cell reaction for the oxidation of H₂O(l)to O₂(g)is given below. 2H₂O(l) $\rarr$ O₂(g)+ 4H⁺(aq)+ 4e^- Which choice lists all of the following species that can oxidize H₂O to O₂(g)under standard-state conditions? MnO₄^-(aq), Cl₂(g), Pb²⁺(aq), Cl^-(aq), Ag⁺(aq)

Complete and balance the following redox equation.The sum of the smallest whole-number coefficients is MnO₄^- + H⁺ + Br^- $\rarr$ Mn²⁺ + Br₂ + H₂O (acidic solution)

Determine the equilibrium constant for the following reaction at 298 K. 2Fe³⁺(aq)+ H₂O₂(aq) 2H⁺(aq)+ O₂(g)+ 2Fe²⁺(aq).

For the electrochemical cell Ni(s)| Ni²⁺(1 M)|| H⁺(1 M)| H₂(1 atm)| Pt(s), which one of the following changes will cause a decrease in the cell voltage?

Complete and balance the following redox equation.What is the coefficient of H₂S when the equation is balanced using the set of smallest whole-number coefficients? H₂S + MnO₄^- $\rarr$ Mn²⁺ + SO₄^2- (acidic solution)

Given the following cell diagram, Al(s)| Al³⁺(aq)|| Cd²⁺(aq)| Cd (s) What is the balanced overall (net)cell reaction?

Complete and balance the following redox equation using the smallest whole-number coefficients.What is the coefficient of Sn in the balanced equation? Sn + HNO₃ $\rarr$ SnO₂ + NO₂ + H₂O (acidic solution)

For the reaction Ni²⁺(aq)+ 2Fe²⁺(aq) $\rarr$ Ni(s)+ 2Fe³⁺(aq), the standard cell potential E°_cell is

Calculate the cell voltage for the following reaction: Cu²⁺ (0.010 M)+ H₂(1 atm) $\rarr$ Cu(s)+ 2H⁺( pH = 7.0)

Write the balanced overall redox equation for the following cell diagram: Cr(s)| Cr³⁺(aq)|| Sn⁴⁺(aq),Sn²⁺(aq)| Pt(s)

Many different ways have been proposed to make batteries.One cell is set up with copper and lead electrodes in contact with CuSO₄(aq)and Pb(NO₃)₂ (aq), respectively.If the Pb²⁺ and Cu²⁺concentrations are each 1.0 M, what is the overall cell potential?

A battery is constructed by placing copper and lead electrodes in contact with 1.0 molar CuSO₄(aq)and Pb(NO₃)₂ (aq)solutions, respectively.If sulfuric acid is then added to the Pb(NO₃)₂ solution, thereby forming a precipitate of PbSO₄, what will happen to the cell potential?