Chapter 19 Review

Transcription

Chapter 19 Review

Chapter 19 Review
Student: ___________________________________________________________________________
1.
Complete and balance the following redox equation. When properly balanced using the smallest whole-number coefficients,
the coefficient of S is
H2S + HNO3 → S + NO (acidic solution)
A. 1
B. 2
C. 3
D. 5
E. 6
2.
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 → SnO2 + NO2 + H2O (acidic solution)
A. 1
B. 2
C. 3
D. 4
E. 5
3.
Complete and balance the following redox equation. What is the coefficient of H2O when the equation is balanced with the set
of smallest whole-number coefficients?
H2O +MnO4- + I- →MnO2 + IO3- (basic solution)
A. 1
B. 2
C. 4
D. 10
E. none of these
4.
Complete and balance the following redox equation.
Br2 → BrO3- + Br- (basic solution)
The sum of the smallest whole-number coefficients is
A. 9.
B. 12.
C. 18.
D. 21.
E. none of these.
5.
Given the following notation for an electrochemical cell
Pt(s) | H2(g) | H+(aq) || Ag+(aq) | Ag(s),
what is the balanced overall (net) cell reaction?
A. 2H+(aq) + 2Ag+(aq) → H (g) + 2Ag(s)
2
B. H (g) + 2Ag(s) → H+(aq) + 2Ag+(aq)
2
C. 2H+(aq) + 2Ag(s) → H (g) + 2Ag+(aq)
2
D. H (g) + Ag+(aq) → H+(aq) + Ag(s)
2
E. H (g) + 2Ag+(aq) → 2H+(aq) + 2Ag(s)
2
6.
Consider an electrochemical cell constructed from the following half cells, linked by an external circuit and by a KCl salt
bridge.
• an Al(s) electrode in 1.0 M Al(NO3)3 solution
• a Pb(s) electrode in 1.0 M Pb(NO3)2 solution
The balanced overall (net) cell reaction is
A. Pb(s) + Al3+(aq) → Pb2+(aq) + Al(s).
B. 3Pb(s) + 2Al3+(aq) → 3Pb2+(aq) + 2Al(s).
C. 3Pb2+(aq) + 2Al(s) → 3Pb(s) + 2Al3+(aq).
D. Pb2+(aq) + Al(s) → Pb(s) + Al3+(aq).
7.
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 Sn electrode in 1.0 M Sn(NO3 )2 solution
When the cell is running spontaneously, which choice includes only true statements and no false ones?
A. The tin electrode loses mass and the tin electrode is the cathode.
B. The tin electrode gains mass and the tin 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.
E. The iron electrode gains mass and the iron electrode is the cathode.
8.
Calculate the value of E°cell for the following reaction:
2Au(s) + 3Ca2+(aq) → 2Au3+(aq) + 3Ca(s)
A. -4.37 V
B. -1.37 V
C. -11.6 V
D. 1.37 V
E. 4.37 V
9.
Calculate E°cell for a silver-aluminum cell in which the cell reaction is
Al(s) + 3Ag+(aq) → Al3+(aq) + 3Ag(s)
A. -2.46 V
B. 0.86 V
C. -0.86 V
D. 2.46 V
E. none of these
10. Calculate the standard cell emf for the following cell:
Mg |Mg2+ || NO3- (acid soln)| NO(g) | Pt
A. 3.33 V
B. 1.41 V
C. -1.41 V
D. 8.46 V
E. -8.46 V
11. According to the following cell diagram, which chemical species undergoes reduction?
Sn | Sn2+ || NO3- (acid soln), NO(g) | Pt
A. Sn
B. Sn2+
C. NO3D. NO
E. Pt
12. In the following half equation, which is the oxidizing agent?
NO3-(aq) + 4H+(aq) + 3e- → NO(g) + 2H2O
A. NO3B. H+
C. eD. NO
E. H2O
13. Which statement is true for a spontaneous redox reaction carried out at standard-state conditions?
A. E°red is always negative.
B. E°cell is always positive.
C. E°ox is always positive.
D. E°red is always positive.
14. Which one of the following reactions will occur spontaneously at standard-state conditions and 25°C?
A. Mg2+ + Ca →Mg + Ca2+
B. Au + 3K+ → Au3+ + 3K
C. 2Al3+ + 3Fe → 2Al + 3Fe2+
D. Cu + 2H+ → Cu2+ + H
2
15.
Consider the following standard reduction potentials in acid solution:
The strongest reducing agent among those shown above is
A. Fe3+.
B. Fe2+.
C. Br-.
D. Al3+.
E. Al.
16. Consider the following standard reduction potentials in acid solution:
The strongest oxidizing agent listed above is
A. Cr3+.
B. Cr.
C. C.Mn2+.
D. Co2+.
E. E.MnO4-.
17. Using a table of standard electrode potentials, decide which of the following statements is completely true.
A. Cu2+ can oxidize H2, and Fe can reduceMn2+.
B. Ni2+ can oxidize Cu2+, and Fe2+ can reduce H+.
C. Fe2+ can oxidize H2, and Fe2+ can reduce Au3+.
D. Br2 can oxidize Ni, and H2 can reduceMn2+.
E. H+ can oxidize Fe, and Ni can reduce Br2.
18. Using a table of standard reduction potentials, determine which of these reactions (if any) is/are nonspontaneous in the
direction indicated at 25°C.
A. 2Fe3+ + 2Cl- → 2Fe2+ + Cl (g)
2
B. 2Fe3+ + 2Br- → 2Fe2+ + Br (l)
2
C. 2Fe3+ + 2I- → 2Fe2+ + I (s)
2
D. 2Fe3+ + 2Cl- → 2Fe2+ + Cl (g) AND 2Fe3+ + 2Br- → 2Fe2+ + Br (l)
2
2
E. All are spontaneous.
19. Which one of the following reagents is capable of transforming Cu2+(1 M) to Cu(s)?
A. I- (1 M)
B. Ni(s)
C. Al3+(1 M)
D. F- (1 M)
E. Ag(s)
20. Consider the following reaction: 2Fe2+(aq) + Cu2+ → 2Fe3+(aq) + Cu.
When the reaction comes to equilibrium, what is the cell voltage?
A. 0.43 V
B. 1.11 V
C. 0.78 V
D. -0.43 V
E. 0 V
21. Determine the equilibrium constant, Keq, at 25°C for the reaction
2Br- (aq) + I2(s)
A. 5.7 × 10-19
B. 18.30
C. 1.7 × 1054
D. 1.9 × 1018
E. 5.7 × 10-55
Br2(l) + 2I- (aq)
22. 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?
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 these
23. Consider an electrochemical cell with the following cell reaction where all reactants and products are at standard-state
conditions: Cu2+(aq) + H2(g) → Cu(s) + 2H+(aq).
Predict the effect on the emf of this cell of adding NaOH solution to the hydrogen half-cell until the pH equals 7.0.
A. The emf will increase.
B. The emf will decrease.
C. No change in the emf will be observed.
24. Which one of the following reactions must be carried out in an electrolytic cell rather than in an electrochemical cell?
A. Zn2+ + Ca → Zn + Ca2+
B. Al3+ + 3Br- → Al + (3/2)Br
2
C. 2Al + 3Fe2+ → 2Al3+ + 3Fe
D. H + I (s) → 2H+ + 2I2
2
25. Predict the products obtained from electrolysis of a 1 M AlBr3 solution.
Note that
A. Al and Br2
B. Al and O2
C. H2 and O2
D. H2 and Br2
E. Al and H2
26. When an aqueous solution of AgNO3 is electrolyzed, a gas is observed to form at the anode. The gas is
A. H2.
B. O2.
C. NO.
D. NO2.
27. The half-reaction that occurs at the cathode during electrolysis of an aqueous sodium iodide solution is
A. Na+ + e- → Na.
B. Na → Na+ + e-.
C. 2H O + 2e- → H + 2OH-.
2
2
D. I + 2e- → 2I-.
2
E. 2I- → I + 2e-.
2
28. The half-reaction that occurs at the cathode during electrolysis of an aqueous CuCl2 solution is
A. Cu+ + e- → Cu.
B. Cu2+ + e- → Cu+.
C. 2H O + 2e- → H + 2OH-.
2
2
D. Cl + 2e- → 2Cl-.
2
E. 2Cl- → Cl + 2e-.
2
29. Under standard-state conditions, which of the following half-reactions occurs at the cathode during the electrolysis of aqueous
nickel sulfate at 25°C?
A. 2H O → O + 4H+ + 4e2
2
B. Ni2+ + 2e- → Ni
C. 2H O + 2e- → H + 2OH2
2
D. Ni → Ni2+ + 2e-
30. How many coulombs of charge are required to cause reduction of 0.20 mole of Cr3+ to Cr?
A. 0.60 C
B. 3.0 C
C. 2.9 × 104 C
D. 5.8 × 104 C
E. 9.65 × 104 C
31. A metal object is to be gold-plated by an electrolytic procedure using aqueous AuCl3 electrolyte. Calculate the number of
moles of gold deposited in 3.0 min by a constant current of 10. A.
A. 6.2 × 10-3 mol
B. 9.3 × 10-3 mol
C. 1.8 × 10-2 mol
D. 3.5 × 10-5 mol
E. 160 mol
32. How many grams of nickel would be electroplated by passing a constant current of 7.2 A through a solution of NiSO4 for 90.0
min?
A. 0.20 g
B. 0.40 g
C. 12 g
D. 24 g
E. 47 g
33. How many minutes would be required to electroplate 25.0 grams of chromium by passing a constant current of 4.80 amperes
through a solution containing CrCl3?
A. 483 min
B. 161 min
C. 322 min
D. 2.01 × 104 min
E. 1.11 × 104 min
34. Aluminum does not corrode as does iron, because
A. Al does not react with O2.
B. a protective layer of Al2O3 forms on the metal surface.
C. Al is harder to oxidize than is Fe.
D. Fe gives cathodic protection to Al.
E. the electrical circuit cannot be completed on an Al surface.
35. Iron objects such as storage tanks and underground pipelines can be protected from corrosion by connecting them through a
wire to a piece of
A. Pb.
B. Ag.
C. Sn.
D. Mg.
E. Cu.
36. Which element is associated with the term "galvanized"?
A. Ga
B. Zn
C. Cd
D. Hg
E. Pb
37. Which of these metals will be oxidized in hydrochloric acid under standard conditions at 25°C?
A. Ag
B. Au
C. Hg
D. Cu
E. Zn
38. Which of these metals will reduce water to hydrogen in basic solution under standard conditions?
A. Pb
B. Fe
C. Zn
D. Na
E. Ag
Chapter 19 Review Key
1.
Complete and balance the following redox equation. When properly balanced using the smallest whole-number
coefficients, the coefficient of S is
H2S + HNO3 → S + NO (acidic solution)
A.
B.
C.
D.
E.
1
2
3
5
6
Difficulty: Medium
Raymond - 019 Electrochemistry... #1
2.
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 → SnO2 + NO2 + H2O (acidic solution)
A.
B.
C.
D.
E.
1
2
3
4
5
Difficulty: Medium
3.
Complete and balance the following redox equation. What is the coefficient of H2O when the equation is balanced with the
set of smallest whole-number coefficients?
H2O +MnO4- + I- →MnO2 + IO3- (basic solution)
A.
B.
C.
D.
E.
1
2
4
10
none of these
Difficulty: Medium
4.
Complete and balance the following redox equation.
Br2 → BrO3- + Br- (basic solution)
The sum of the smallest whole-number coefficients is
A. 9.
B. 12.
C. 18.
D. 21.
E. none of these.
Difficulty: Medium
5.
Given the following notation for an electrochemical cell
Pt(s) | H2(g) | H+(aq) || Ag+(aq) | Ag(s),
what is the balanced overall (net) cell reaction?
A. 2H+(aq) + 2Ag+(aq) → H (g) + 2Ag(s)
2
B. H (g) + 2Ag(s) → H+(aq) + 2Ag+(aq)
2
C. 2H+(aq) + 2Ag(s) → H (g) + 2Ag+(aq)
2
D. H (g) + Ag+(aq) → H+(aq) + Ag(s)
2
E. H (g) + 2Ag+(aq) → 2H+(aq) + 2Ag(s)
2
Difficulty: Medium
6.
Consider an electrochemical cell constructed from the following half cells, linked by an external circuit and by a KCl salt
bridge.
• an Al(s) electrode in 1.0 M Al(NO3)3 solution
• a Pb(s) electrode in 1.0 M Pb(NO3)2 solution
The balanced overall (net) cell reaction is
A. Pb(s) + Al3+(aq) → Pb2+(aq) + Al(s).
B. 3Pb(s) + 2Al3+(aq) → 3Pb2+(aq) + 2Al(s).
C. 3Pb2+(aq) + 2Al(s) → 3Pb(s) + 2Al3+(aq).
D. Pb2+(aq) + Al(s) → Pb(s) + Al3+(aq).
Difficulty: Medium
7.
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 Sn electrode in 1.0 M Sn(NO3 )2 solution
When the cell is running spontaneously, which choice includes only true statements and no false ones?
A. The tin electrode loses mass and the tin electrode is the cathode.
B. The tin electrode gains mass and the tin 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.
E. The iron electrode gains mass and the iron electrode is the cathode.
Difficulty: Medium
8.
Calculate the value of E°cell for the following reaction:
A.
B.
C.
D.
E.
2Au(s) + 3Ca2+(aq) → 2Au3+(aq) + 3Ca(s)
-4.37 V
-1.37 V
-11.6 V
1.37 V
4.37 V
Difficulty: Medium
9.
Calculate E°cell for a silver-aluminum cell in which the cell reaction is
A.
B.
C.
D.
E.
Al(s) + 3Ag+(aq) → Al3+(aq) + 3Ag(s)
-2.46 V
0.86 V
-0.86 V
2.46 V
none of these
Difficulty: Medium
10.
Calculate the standard cell emf for the following cell:
Mg |Mg2+ || NO3- (acid soln)| NO(g) | Pt
A. 3.33 V
B. 1.41 V
C. -1.41 V
D. 8.46 V
E. -8.46 V
Difficulty: Medium
11.
According to the following cell diagram, which chemical species undergoes reduction?
Sn | Sn2+ || NO3- (acid soln), NO(g) | Pt
A. Sn
B. Sn2+
C. NO3D. NO
E. Pt
Difficulty: Medium
12.
In the following half equation, which is the oxidizing agent?
NO3-(aq) + 4H+(aq) + 3e- → NO(g) + 2H2O
A.
B.
C.
D.
E.
NO3H+
eNO
H2O
Difficulty: Medium
13.
Which statement is true for a spontaneous redox reaction carried out at standard-state conditions?
A. E°red is always negative.
B. E°cell is always positive.
C. E°ox is always positive.
D. E°red is always positive.
Difficulty: Easy
14.
Which one of the following reactions will occur spontaneously at standard-state conditions and 25°C?
A. Mg2+ + Ca →Mg + Ca2+
B. Au + 3K+ → Au3+ + 3K
C. 2Al3+ + 3Fe → 2Al + 3Fe2+
D. Cu + 2H+ → Cu2+ + H
2
Difficulty: Medium
15.
The strongest reducing agent among those shown above is
A. Fe3+.
B. Fe2+.
C. Br-.
D. Al3+.
E. Al.
Difficulty: Medium
16.
The strongest oxidizing agent listed above is
A. Cr3+.
B. Cr.
C. C.Mn2+.
D. Co2+.
E. E.MnO4-.
Difficulty: Medium
17.
Using a table of standard electrode potentials, decide which of the following statements is completely true.
A. Cu2+ can oxidize H2, and Fe can reduceMn2+.
B. Ni2+ can oxidize Cu2+, and Fe2+ can reduce H+.
C. Fe2+ can oxidize H2, and Fe2+ can reduce Au3+.
D. Br2 can oxidize Ni, and H2 can reduceMn2+.
E. H+ can oxidize Fe, and Ni can reduce Br2.
Difficulty: Medium
18.
Using a table of standard reduction potentials, determine which of these reactions (if any) is/are nonspontaneous in the
direction indicated at 25°C.
A. 2Fe3+ + 2Cl- → 2Fe2+ + Cl (g)
2
B. 2Fe3+ + 2Br- → 2Fe2+ + Br (l)
2
C. 2Fe3+ + 2I- → 2Fe2+ + I (s)
2
D. 2Fe3+ + 2Cl- → 2Fe2+ + Cl (g) AND 2Fe3+ + 2Br- → 2Fe2+ + Br (l)
2
2
E. All are spontaneous.
19.
Which one of the following reagents is capable of transforming
A. I- (1 M)
B. Ni(s)
C. Al3+(1 M)
D. F- (1 M)
E. Ag(s)
Cu2+(1
Difficulty: Medium
M) to Cu(s)?
Difficulty: Medium
20.
Consider the following reaction: 2Fe2+(aq) + Cu2+ → 2Fe3+(aq) + Cu.
When the reaction comes to equilibrium, what is the cell voltage?
A. 0.43 V
B. 1.11 V
C. 0.78 V
D. -0.43 V
E. 0 V
Difficulty: Easy
21.
Determine the equilibrium constant, Keq, at 25°C for the reaction
A.
B.
C.
D.
E.
2Br- (aq) + I2(s)
5.7 × 10-19
18.30
1.7 × 1054
1.9 × 1018
5.7 × 10-55
Br2(l) + 2I- (aq)
Difficulty: Medium
22.
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?
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 these
Difficulty: Medium
23.
Consider an electrochemical cell with the following cell reaction where all reactants and products are at standard-state
conditions: Cu2+(aq) + H2(g) → Cu(s) + 2H+(aq).
Predict the effect on the emf of this cell of adding NaOH solution to the hydrogen half-cell until the pH equals 7.0.
A. The emf will increase.
B. The emf will decrease.
C. No change in the emf will be observed.
Difficulty: Medium
24.
Which one of the following reactions must be carried out in an electrolytic cell rather than in an electrochemical cell?
A. Zn2+ + Ca → Zn + Ca2+
B. Al3+ + 3Br- → Al + (3/2)Br
2
C. 2Al + 3Fe2+ → 2Al3+ + 3Fe
D. H + I (s) → 2H+ + 2I2
2
Difficulty: Medium
25.
Predict the products obtained from electrolysis of a 1 M AlBr3 solution.
Note that
A.
B.
C.
D.
E.
Al and Br2
Al and O2
H2 and O2
H2 and Br2
Al and H2
Difficulty: Difficult
26.
When an aqueous solution of AgNO3 is electrolyzed, a gas is observed to form at the anode. The gas is
A. H2.
B. O2.
C. NO.
D. NO2.
27.
The half-reaction that occurs at the cathode during electrolysis of an aqueous sodium iodide solution is
A. Na+ + e- → Na.
B. Na → Na+ + e-.
C. 2H O + 2e- → H + 2OH-.
2
2
D. I + 2e- → 2I-.
2
E. 2I- → I + 2e-.
2
28.
The half-reaction that occurs at the cathode during electrolysis of an aqueous CuCl2 solution is
A. Cu+ + e- → Cu.
B. Cu2+ + e- → Cu+.
C. 2H O + 2e- → H + 2OH-.
2
2
D. Cl + 2e- → 2Cl-.
2
E. 2Cl- → Cl + 2e-.
2
29.
Under standard-state conditions, which of the following half-reactions occurs at the cathode during the electrolysis of
aqueous nickel sulfate at 25°C?
A. 2H O → O + 4H+ + 4e2
2
B. Ni2+ + 2e- → Ni
C. 2H O + 2e- → H + 2OH2
2
D. Ni → Ni2+ + 2eDifficulty: Difficult
30.
How many coulombs of charge are required to cause reduction of 0.20 mole of Cr3+ to Cr?
A. 0.60 C
B. 3.0 C
C. 2.9 × 104 C
D. 5.8 × 104 C
E. 9.65 × 104 C
Difficulty: Easy
31.
A metal object is to be gold-plated by an electrolytic procedure using aqueous AuCl3 electrolyte. Calculate the number of
moles of gold deposited in 3.0 min by a constant current of 10. A.
A. 6.2 × 10-3 mol
B. 9.3 × 10-3 mol
C. 1.8 × 10-2 mol
D. 3.5 × 10-5 mol
E. 160 mol
Difficulty: Medium
32.
How many grams of nickel would be electroplated by passing a constant current of 7.2 A through a solution of NiSO4 for
90.0 min?
A. 0.20 g
B. 0.40 g
C. 12 g
D. 24 g
E. 47 g
Difficulty: Medium
33.
How many minutes would be required to electroplate 25.0 grams of chromium by passing a constant current of 4.80
amperes through a solution containing CrCl3?
A. 483 min
B. 161 min
C. 322 min
D. 2.01 × 104 min
E. 1.11 × 104 min
Difficulty: Medium
34.
Aluminum does not corrode as does iron, because
A. Al does not react with O2.
B. a protective layer of Al2O3 forms on the metal surface.
C. Al is harder to oxidize than is Fe.
D. Fe gives cathodic protection to Al.
E. the electrical circuit cannot be completed on an Al surface.
Difficulty: Medium
35.
Iron objects such as storage tanks and underground pipelines can be protected from corrosion by connecting them through
a wire to a piece of
A. Pb.
B. Ag.
C. Sn.
D. Mg.
E. Cu.
Difficulty: Medium
36.
Which element is associated with the term "galvanized"?
A. Ga
B. Zn
C. Cd
D. Hg
E. Pb
Difficulty: Easy
37.
Which of these metals will be oxidized in hydrochloric acid under standard conditions at 25°C?
A. Ag
B. Au
C. Hg
D. Cu
E. Zn
38.
Which of these metals will reduce water to hydrogen in basic solution under standard conditions?
A. Pb
B. Fe
C. Zn
D. Na
E. Ag
Chapter 19 Review Summary
Category
Difficulty: Easy
Difficulty: Medium
Raymond - 019 Electrochemistry...
# of Questions
7
4
27
38

Chapter 19 Review

Transcription

Similar documents

NEVER WELD UPSIDE DOWN NUTS AGAIN!

Spring Breakers - Venus Over Manhattan

for the complete man

,2/12/02 1u:uz YM +UYUU, rwa: r w : An mreresmg mt on ixxon

CorClub brochure and application

Giant Robot

Attachments

Raymond the Rhino

LENÔTRE, GASTRONOMIC EXCELLENCE