Question 1

Determine the equilibrium constant (Keq)at 25°C for the reaction Cl2(g)+ 2Br- (aq)   NEWLINE
2Cl- (aq)+ Br2(l)

Accepted Answer

A) 1.5 × 10-10 
B) 6.3 × 109 
C) 1.3 × 1041 
D) 8.1 × 104 
E) 9.8 
A) 1.5 × 10-10 
B) 6.3 × 109 
C) 1.3 × 1041 
D) 8.1 × 104 
E) 9.8 B

Question 2

Complete and balance the following redox reaction under acidic conditions:
Cr2O72-(aq)+ I-(aq)$\rarr$0 Cr3+(aq)+ IO3-(aq)

Accepted Answer

Cr₂O₇^2-(aq)+ I^-(aq)+ 8H⁺(aq)$\rarr$2Cr³⁺(aq)+ IO₃^-(aq)+ 4H₂O(l)

Question 3

Write the formula of the weakest reducing agent.given the following standard reduction potentials in acid solution

Accepted Answer

H<sub>2</sub>O

Question 4

Consider the reaction Hg2+(aq)+ Hg(l)     Hg22+(aq).Find the equilibrium constant for this reaction at 25°C.

Accepted Answer

A) 2 × 101 
B) 6 × 1059 
C) 4 × 10-3 
D) 7 × 10-2 
E) 2 × 102 
A) 2 × 101 
B) 6 × 1059 
C) 4 × 10-3 
D) 7 × 10-2 
E) 2 × 102

Question 5

Which one of the following reactions will occur spontaneously at standard-state conditions and 25°C?

Accepted Answer

A) Br2(l)+ Sn(s)$\rarr$2Br-(aq)+ Sn2+(aq) 
B) Fe2+(aq)+ Ni(s)$\rarr$ Fe(s)+ Ni2+(aq) 
C) 2Ag+(aq)2H2O(l)$\rarr$ 2Ag(s)+ 2H+(aq)+ H2O2(aq) 
D) Mn2+(aq)+ Cd(s)$\rarr$ Mn(s)+ Cd2+(aq) 
E) Cr3+(aq)+ 3Cu+(aq)$\rarr$ Cr(s)+ 3Cu2+(aq) 
A) Br2(l)+ Sn(s)$\rarr$2Br-(aq)+ Sn2+(aq) 
B) Fe2+(aq)+ Ni(s)$\rarr$ Fe(s)+ Ni2+(aq) 
C) 2Ag+(aq)2H2O(l)$\rarr$ 2Ag(s)+ 2H+(aq)+ H2O2(aq) 
D) Mn2+(aq)+ Cd(s)$\rarr$ Mn(s)+ Cd2+(aq) 
E) Cr3+(aq)+ 3Cu+(aq)$\rarr$ Cr(s)+ 3Cu2+(aq)

Question 6

Which one of the following is consistent with a dead battery (an electrochemical cell at equilibrium)?

Accepted Answer

A) ($\Delta$G = 0, Ecell = 0, Q = K) 
B) ($\Delta$G cell > 0, Q cell  0, Ecell  0, Ecell = 0, Q > K) 
A) ($\Delta$G = 0, Ecell = 0, Q = K) 
B) ($\Delta$G cell > 0, Q cell  0, Ecell  0, Ecell = 0, Q > K)

Question 7

If the cell emf of a Zn-Cu cell is 0.80 V when the concentration of Zn2+ is 2.0 M, what is the concentration of Cu2+?

Accepted Answer

Question 8

Predict the products of the electrolysis of aqueous potassium chloride KCl(aq)

Accepted Answer

A) Cl-(aq)and K(s) 
B) Cl2(g)and K(s) 
C) Cl2(g)and H2(g)and OH-(aq) 
D) Cl2(g)and K+(aq) 
E) Cl-(aq)and K+(aq) 
A) Cl-(aq)and K(s) 
B) Cl2(g)and K(s) 
C) Cl2(g)and H2(g)and OH-(aq) 
D) Cl2(g)and K+(aq) 
E) Cl-(aq)and K+(aq)

Question 9

A galvanic cell has the overall reaction: 2Fe(NO3)2(aq)+ Pb(NO3)2(aq)$\rarr$2Fe(NO3)3(aq)+ Pb(s)
Which is the half reaction occurring at the cathode?

Accepted Answer

A) NO3-(aq)+ 4H+(aq)+ 3e- $\rarr$ NO(g)+ 2H2O(l) 
B) NO3-(aq)+ 2H+(aq)+ e- $\rarr$ NO2(g)+ H2O(l) 
C) Fe2+(aq)$\rarr$Fe3+(aq)+ e- 
D) Pb2+(aq)+ 2e-$\rarr$ Pb(s) 
E) Fe2+(aq)+ e- $\rarr$ Fe3+(aq) 
A) NO3-(aq)+ 4H+(aq)+ 3e- $\rarr$ NO(g)+ 2H2O(l) 
B) NO3-(aq)+ 2H+(aq)+ e- $\rarr$ NO2(g)+ H2O(l) 
C) Fe2+(aq)$\rarr$Fe3+(aq)+ e- 
D) Pb2+(aq)+ 2e-$\rarr$ Pb(s) 
E) Fe2+(aq)+ e- $\rarr$ Fe3+(aq)

Question 10

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

Accepted Answer

A) Zn2+(aq) + Ca(s)$\rarr$ Zn(s)+ Ca2+(aq) 
B) Al3+(aq)+ 3Br-(aq)$\rarr$ Al(s)+ (3/2)Br2(l) 
C) 2Al(s)+ 3Fe2+(aq)$\rarr$ 2Al3+(aq)+ 3Fe(s) 
D) H2(g)+ I2(s)$\rarr$2H+(aq)+ 2I-(aq) 
E) Fe2+(aq)+ Mg(s)$\rarr$ Fe(s)+ Mg2+(aq) 
A) Zn2+(aq) + Ca(s)$\rarr$ Zn(s)+ Ca2+(aq) 
B) Al3+(aq)+ 3Br-(aq)$\rarr$ Al(s)+ (3/2)Br2(l) 
C) 2Al(s)+ 3Fe2+(aq)$\rarr$ 2Al3+(aq)+ 3Fe(s) 
D) H2(g)+ I2(s)$\rarr$2H+(aq)+ 2I-(aq) 
E) Fe2+(aq)+ Mg(s)$\rarr$ Fe(s)+ Mg2+(aq)

Question 11

Consider the following standard reduction potentials in acid solution:   The strongest 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 12

Consider an electrochemical cell constructed from the following half cells, linked by a KCl salt bridge. - a Fe electrode in 1.0 M FeCl2 solution
- a Ni electrode in 1.0 M Ni(NO3)2 solution
When the cell is running spontaneously, which choice includes only true statements and no false ones?

Accepted Answer

A) The nickel electrode loses mass and the nickel electrode is the cathode. 
B) The nickel electrode gains mass and the nickel electrode is the cathode. 
C) The iron electrode gains mass and the iron electrode is the anode. 
D) The iron electrode loses mass and the iron electrode is the cathode. 
A) The nickel electrode loses mass and the nickel electrode is the cathode. 
B) The nickel electrode gains mass and the nickel electrode is the cathode. 
C) The iron electrode gains mass and the iron electrode is the anode. 
D) The iron electrode loses mass and the iron electrode is the cathode.

Question 13

Calculate the value of E°cell for the following reaction: 2Au(s)+ 3Ca2+(aq)$\rarr$ 2Au3+(aq)+ 3Ca(s)

Accepted Answer

A) -4.37 V 
B) -1.37 V 
C) -11.6 V 
D) 1.37 V 
E) 4.37 V 
A) -4.37 V 
B) -1.37 V 
C) -11.6 V 
D) 1.37 V 
E) 4.37 V

Question 14

Complete and balance the following redox equation using the set of smallest whole-number coefficients.Now sum the coefficients of all species in the balanced equation.(Remember the coefficients that are equal to one.)The sum of the coefficients is BrO3-(aq)+ Sb3+(aq)$\rarr$Br-(aq)+ Sb5+(aq)(acidic solution)

Accepted Answer

A) 4 
B) 12 
C) 13 
D) 17 
E) None of these. 
A) 4 
B) 12 
C) 13 
D) 17 
E) None of these.

Question 15

The half-reaction occurring at the cathode during electrolysis of an aqueous copper(II)iodide solution is

Accepted Answer

A) I2 + 2e- $\rarr$ 2I-. 
B) Cu $\rarr$ Cu2+ + 2e-. 
C) Cu2+ + 2e- $\rarr$ Cu. 
D) 2I-  $\rarr$I2 + 2e-. 
E) 2e- + 2H2O $\rarr$ H2 + 2OH-. 
A) I2 + 2e- $\rarr$ 2I-. 
B) Cu $\rarr$ Cu2+ + 2e-. 
C) Cu2+ + 2e- $\rarr$ Cu. 
D) 2I-  $\rarr$I2 + 2e-. 
E) 2e- + 2H2O $\rarr$ H2 + 2OH-.

Question 16

Which one of the following reactions will occur spontaneously at standard-state conditions and 25°C?

Accepted Answer

A) Mg2+ + Ca $\rarr$ Mg + Ca2+ 
B) Au + 3K+ $\rarr$ Au3+ + 3K 
C) 2Al3+ + 3Fe $\rarr$2Al + 3Fe2+ 
D) Cu + 2H+ $\rarr$ Cu2+ + H2 
E) Ni2+ + 2Fe2+(aq)$\rarr$ Ni(s)+ 2Fe3+(aq) 
A) Mg2+ + Ca $\rarr$ Mg + Ca2+ 
B) Au + 3K+ $\rarr$ Au3+ + 3K 
C) 2Al3+ + 3Fe $\rarr$2Al + 3Fe2+ 
D) Cu + 2H+ $\rarr$ Cu2+ + H2 
E) Ni2+ + 2Fe2+(aq)$\rarr$ Ni(s)+ 2Fe3+(aq)

Question 17

Aluminum metal is formed by the electrolysis of Al2O3 in molten cryolite.How many minutes are required to form 10.0 g of Al using a current of 30 A?

Accepted Answer

Question 18

Consider the following standard reduction potentials in acid solution:   Which is the weakest oxidizing agent in this list?

Accepted Answer

A) Al3+(aq) 
B) Al(s) 
C) I-(aq) 
D) I2(s) 
E) Sn4+(aq) 
A) Al3+(aq) 
B) Al(s) 
C) I-(aq) 
D) I2(s) 
E) Sn4+(aq)

Question 19

You wish to electroplate a metal utensil with a surface area of 736 cm2 with gold to give an average thickness of 0.025 mm over the entire surface.Starting with a solution of excess Au3+ and applying a constant current of 14 A, how long will it take to electroplate the utensil? The density of gold is 19.3 g/cm3.

Accepted Answer

Question 20

Will H2(g)form when Sn is placed in 1.0 M HCl?

Accepted Answer

Exam 18: Electrochemistry

Determine the equilibrium constant (Keq)at 25°C for the reaction Cl2(g)+ 2Br- (aq) NEWLINE 2Cl- (aq)+ Br2(l)

Complete and balance the following redox reaction under acidic conditions: Cr2O72-(aq)+ I-(aq) →\rarr→ 0 Cr3+(aq)+ IO3-(aq)

Write the formula of the weakest reducing agent.given the following standard reduction potentials in acid solution

Consider the reaction Hg2+(aq)+ Hg(l) Hg22+(aq).Find the equilibrium constant for this reaction at 25°C.

Which one of the following reactions will occur spontaneously at standard-state conditions and 25°C?

Which one of the following is consistent with a dead battery (an electrochemical cell at equilibrium)?

If the cell emf of a Zn-Cu cell is 0.80 V when the concentration of Zn2+ is 2.0 M, what is the concentration of Cu2+?

Predict the products of the electrolysis of aqueous potassium chloride KCl(aq)

A galvanic cell has the overall reaction: 2Fe(NO3)2(aq)+ Pb(NO3)2(aq) →\rarr→ 2Fe(NO3)3(aq)+ Pb(s) Which is the half reaction occurring at the cathode?

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 listed above is

Consider an electrochemical cell constructed from the following half cells, linked by a KCl salt bridge. - a Fe electrode in 1.0 M FeCl2 solution - a Ni electrode in 1.0 M Ni(NO3)2 solution When the cell is running spontaneously, which choice includes only true statements and no false ones?

Calculate the value of E°cell for the following reaction: 2Au(s)+ 3Ca2+(aq) →\rarr→ 2Au3+(aq)+ 3Ca(s)

The half-reaction occurring at the cathode during electrolysis of an aqueous copper(II)iodide solution is

Which one of the following reactions will occur spontaneously at standard-state conditions and 25°C?

Aluminum metal is formed by the electrolysis of Al2O3 in molten cryolite.How many minutes are required to form 10.0 g of Al using a current of 30 A?

Consider the following standard reduction potentials in acid solution: Which is the weakest oxidizing agent in this list?

Will H2(g)form when Sn is placed in 1.0 M HCl?

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Filters

Determine the equilibrium constant (K_eq)at 25°C for the reaction Cl₂(g)+ 2Br^-(aq) _NEW_LINE 2Cl^-(aq)+ Br₂(l)

Complete and balance the following redox reaction under acidic conditions: Cr₂O₇^2-(aq)+ I^-(aq) $\rarr$ 0 Cr³⁺(aq)+ IO₃^-(aq)

Consider the reaction Hg²⁺(aq)+ Hg(l) Hg₂²⁺(aq).Find the equilibrium constant for this reaction at 25°C.

If the cell emf of a Zn-Cu cell is 0.80 V when the concentration of Zn²⁺ is 2.0 M, what is the concentration of Cu²⁺?

A galvanic cell has the overall reaction: 2Fe(NO₃)₂(aq)+ Pb(NO₃)₂(aq) $\rarr$ 2Fe(NO₃)₃(aq)+ Pb(s) Which is the half reaction occurring at the cathode?

Consider an electrochemical cell constructed from the following half cells, linked by a KCl salt bridge. - a Fe electrode in 1.0 M FeCl₂ solution - a Ni electrode in 1.0 M Ni(NO₃)₂ solution When the cell is running spontaneously, which choice includes only true statements and no false ones?

Calculate the value of E°_cell for the following reaction: 2Au(s)+ 3Ca²⁺(aq) $\rarr$ 2Au³⁺(aq)+ 3Ca(s)

Aluminum metal is formed by the electrolysis of Al₂O₃in molten cryolite.How many minutes are required to form 10.0 g of Al using a current of 30 A?

Will H₂(g)form when Sn is placed in 1.0 M HCl?