Problem 40a
A voltaic cell that uses the reaction PdCl42-(aq) + Cd(s) → Pd(s) + 4 Cl-(aq) + Cd2+(aq) has a measured standard cell potential of +1.03 V. (a) Write the two half-cell reactions.
Problem 40b
A voltaic cell that uses the reaction PdCl42-(aq) + Cd(s) → Pd(s) + 4 Cl-(aq) + Cd2+(aq) has a measured standard cell potential of +1.03 V. (b) By using data from Appendix E, determine E°red for the reaction involving Pd.
Problem 40c
A voltaic cell that uses the reaction PdCl42-(aq) + Cd(s) → Pd(s) + 4 Cl-(aq) + Cd2+(aq) has a measured standard cell potential of +1.03 V. (c) Sketch the voltaic cell, label the anode and cathode, and indicate the direction of electron flow
Problem 41a
Using standard reduction potentials (Appendix E), calculate the standard emf for each of the following reactions: (a) Cl21g2 + 2 I-1aq2 ¡ 2 Cl-1aq2 + I21s2
Problem 41b
Using standard reduction potentials (Appendix E), calculate the standard emf for each of the following reactions: (b) Ni1s2 + 2 Ce4+1aq2 ¡ Ni2+1aq2 + 2 Ce3+1aq2
Problem 41c
Using standard reduction potentials (Appendix E), calculate the standard emf for each of the following reactions: (c) Fe1s2 + 2 Fe3+1aq2 ¡ 3 Fe2+1aq2
Problem 41d
Using standard reduction potentials (Appendix E), calculate the standard emf for each of the following reactions: (d) 2 NO3-1aq2 + 8 H+1aq2 + 3 Cu1s2 ¡ 2 NO1g2 + 4 H2O1l2 + 3 Cu2+1aq2
- Using data in Appendix E, calculate the standard emf for each of the following reactions: (a) H2(g) + F2(g) → 2 H+(aq) + 2 F-(aq) (b) Cu2+(aq) + Ca(s) → Cu(s) + Ca2+(aq) (c) 3 Fe2+(aq) → Fe(s) + 2 Fe3+(aq) (d) 2 ClO3-(aq) + 10 Br-(aq) + 12 H+(aq) → Cl2(g) + 5 Br2(l) + 6 H2O(l)
Problem 42
Problem 43
The standard reduction potentials of the following halfreactions are given in Appendix E:
Ag+(aq) + e- → Ag(s)
Cu2+(aq) + 2 e- → Cu(s)
Ni2+(aq) + 2 e- → Ni(s)
Cr3+(aq) + 3 e- → Cr(s)
(a) Determine which combination of these half-cell reactions leads to the cell reaction with the largest positive cell potential and calculate the value.
(b) Determine which combination of these half-cell reactions leads to the cell reaction with the smallest positive cell potential and calculate the value.
- A 1 M solution of Cu(NO3)2 is placed in a beaker with a strip of Cu metal. A 1 M solution of SnSO4 is placed in a second beaker with a strip of Sn metal. A salt bridge connects the two beakers, and wires to a voltmeter link the two metal electrodes. (a) Which electrode serves as the anode, and which as the cathode? (b) Which electrode gains mass, and which loses mass as the cell reaction proceeds?
Problem 45
Problem 46
A voltaic cell consists of a strip of cadmium metal in a solution of Cd(NO3)2 in one beaker, and in the other beaker a platinum electrode is immersed in a NaCl solution, with Cl2 gas bubbled around the electrode. A salt bridge connects the two beakers. (a) Which electrode serves as the anode, and which as the cathode? (b) Does the Cd electrode gain or lose mass as the cell reaction proceeds? (c) Write the equation for the overall cell reaction.
Problem 47a,b,c
From each of the following pairs of substances, use data in Appendix E to choose the one that is the stronger reducing agent: (a) Fe(s) or Mg(s) (b) Ca(s) or Al(s) (c) H2(g, acidic solution) or H2S(g)
- From each of the following pairs of substances, use data in Appendix E to choose the one that is the stronger oxidizing agent: (a) Cl2(g) or Br2(l) (b) Zn2+(aq) or Cd2+(aq) (c) Cl-(aq) or ClO3-(aq) (d) H2O2(aq) or O3(g)
Problem 48
Problem 49a,b,c
By using the data in Appendix E, determine whether each of the following substances is likely to serve as an oxidant or a reductant: (a) Cl2(g), (b) MnO4- (aq, acidic solution), (c) Ba(s)
Problem 49d
By using the data in Appendix E, determine whether each of the following substances is likely to serve as an oxidant or a reductant: (d) Zn(s)
Problem 50
Is each of the following substances likely to serve as an oxidant or a reductant: (a) Ce3+(aq) (b) Ca(s) (c) ClO3-(aq) (d) N2O5(g)?
Problem 51a
(a) Assuming standard conditions, arrange the following in order of increasing strength as oxidizing agents in acidic solution: Cr2O72-, H2O2, Cu2+, Cl2, O2.
Problem 51b
(b) Arrange the following in order of increasing strength as reducing agents in acidic solution: Zn, I-, Sn2+, H2O2, Al.
- Based on the data in Appendix E, (a) which of the following is the strongest oxidizing agent, and which is the weakest in acidic solution: Br2, H2O2, Zn, Cr2O72-?
Problem 52
- The standard reduction potential of Eu2+(aq) is -0.43 V. Using Appendix E, which of the following substances is capable of reducing Eu3+(aq) to Eu2+(aq) under standard conditions: Al, Co, H2O2, N2H5+, H2C2O4?
Problem 53
Problem 55a
Given the following reduction half-reactions:
Fe3+(aq) + e- → Fe2+(aq) E°red = +0.77 V
S2O62-(aq) + 4 H+(aq) + 2 e- → 2 H2SO3(aq) E°red = +0.60 V
N2O(g) + 2 H+(aq) + 2 e- → N2(g) + H2O(l) E°red = -1.77 V
VO2+(aq) + 2 H+(aq) + e- → VO2+ + H2O(l) E°red = +1.00 V
(a) Write balanced chemical equations for the oxidation of Fe2+(aq) by S2O62-(aq), by N2O(aq), and by VO2+(aq).
Problem 55b
Given the following reduction half-reactions:
Fe3+(aq) + e- → Fe2+(aq) E°red = +0.77 V
S2O62-(aq) + 4 H+(aq) + 2 e- → 2 H2SO3(aq) E°red = +0.60 V
N2O(g) + 2 H+(aq) + 2 e- → N2(g) + H2O(l) E°red = -1.77 V
VO2+(aq) + 2 H+(aq) + e- → VO2+ + H2O(l) E°red = +1.00 V
(b) Calculate ∆G° for each reaction at 298 K.
Problem 56
Given the following reduction half-reactions:
Fe3+(aq) + e- → Fe2+(aq) E°red = +0.77 V
S2O62-(aq) + 4 H+(aq) + 2 e- → 2 H2SO3(aq) E°red = +0.60 V
N2O(g) + 2 H+(aq) + 2 e- → N2(g) + H2O(l) E°red = -1.77 V
VO2+(aq) + 2 H+(aq) + e- → VO2+ + H2O(l) E°red = +1.00 V
(c) Calculate the equilibrium constant K for each reaction at 298 K.
Problem 56a
For each of the following reactions, write a balanced equation, calculate the standard emf, calculate ∆G° at 298 K, and calculate the equilibrium constant K at 298 K. (a) Aqueous iodide ion is oxidized to I21s2 by Hg22+1aq2.
Problem 56b
For each of the following reactions, write a balanced equation, calculate the standard emf, calculate ∆G° at 298 K, and calculate the equilibrium constant K at 298 K. (b) In acidic solution, copper(I) ion is oxidized to copper(II) ion by nitrate ion.
Problem 56c
For each of the following reactions, write a balanced equation, calculate the standard emf, calculate ∆G° at 298 K, and calculate the equilibrium constant K at 298 K. (c) In basic solution, Cr1OH231s2 is oxidized to CrO42-1aq2 by ClO-1aq2.
- If the equilibrium constant for a two-electron redox reaction at 298 K is 1.5 * 10⁻⁴, calculate the corresponding ∆G° and E°.
Problem 57
Problem 57d
From each of the following pairs of substances, use data in Appendix E to choose the one that is the stronger reducing agent: (d) BrO3-1aq2 or IO3-1aq2
- If the equilibrium constant for a one-electron redox reaction at 298 K is 8.7 * 10^4, calculate the corresponding ∆G° and E°.
Problem 58
Problem 59
Using the standard reduction potentials listed in Appendix E, calculate the equilibrium constant for each of the following reactions at 298 K:
(a) Fe(s) + Ni2+(aq) → Fe2+(aq) + Ni(s)
(b) Co(s) + 2 H+(aq) → Co2+(aq) + H2(g)
(c) 10 Br-(aq) + 2 MnO4-(aq) + 16 H+(aq) → 2 Mn2+(aq) + 8 H2O(l) + 5 Br2(l)
Ch.20 - Electrochemistry