Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780137542970

Ch.20 - Electrochemistry

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모든 교과서

Brown 15th Edition

Ch.20 - Electrochemistry

문제 24

Complete and balance the following half-reactions in basic solution. In each case, indicate whether the half-reaction is an oxidation or a reduction.

a. OH−(𝑎𝑞)⟶O2(𝑔)

b. SO32−(𝑎𝑞)⟶SO42−(𝑎𝑞)

c. N2(𝑔)⟶NH3(𝑔)

d. HO2−(𝑎𝑞)⟶OH−(𝑎𝑞)

문제 24b

Complete and balance the following half-reactions. In each case, indicate whether the half-reaction is an oxidation or a reduction. (f) SO32-1aq2 ¡ SO42-1aq2 (basic solution)

문제 25

Complete and balance the following half-reactions in basic solution. In each case, indicate whether the half-reaction is an oxidation or a reduction.

a. O2(𝑔)⟶H2O(𝑙)

b. Mn2+(𝑎𝑞)⟶MnO2(𝑠)

c. Cr(OH)3(𝑠)⟶CrO42−(𝑎𝑞)

d. N2H4(𝑎𝑞)⟶N2(𝑔)

문제 25c

Complete and balance the following half-reactions in basic solution. In each case, indicate whether the half-reaction is an oxidation or a reduction. c. Cr(OH)3(𝑠)⟶CrO42−(𝑎𝑞)

문제 26b

Complete and balance the following half-reactions in acidic solution. In each case indicate whether the half-reaction is an oxidation or a reduction. b. H2SO3(𝑎𝑞)⟶SO42−(𝑎𝑞)

문제 27a,b,c

Complete and balance the following equations, and identify the oxidizing and reducing agents: (a) Cr₂O₇^2-(aq) + I^-(aq) → Cr³⁺(aq) + IO₃^-(aq) (acidic solution) (b) MnO₄^-(aq) + CH₃O(1aq) → Mn²⁺(aq) + HCOOH(aq) (acidic solution) (c) I₂(s) + OCl^-(aq) → IO₃^-(aq) + Cl^-(aq) (acidic solution)

문제 27c

Complete and balance the following equations, and identify the oxidizing and reducing agents: MnO₄^-(aq) + Br^-(aq) → MnO₂(s) + BrO₃^-(aq) (basic solution)

문제 28

Complete and balance the following equations, and identify the oxidizing and reducing agents:

a. MnO4−(𝑎𝑞)+CH3OH(𝑎𝑞)⟶Mn2+(𝑎𝑞)+HCOOH(𝑎𝑞)(acidic solution)

b. As2O3(𝑠)+NO3−(𝑎𝑞)⟶H3AsO4(𝑎𝑞)+N2O3(𝑎𝑞)(acidic solution)

c. Pb(OH)42−(𝑎𝑞)+ClO−(𝑎𝑞)⟶PbO2(𝑠)+Cl−(𝑎𝑞)(basic solution)

문제 28b

Complete and balance the following equations, and identify the oxidizing and reducing agents: As₂O₃(s) + NO₃^-(aq) → H₃AsO₄(aq) + N₂O₃(aq) (acidic solution)

문제 29a,b,c,d

Complete and balance the following equations, and identify the oxidizing and reducing agents. (Recall that the O atoms in hydrogen peroxide, H₂O₂, have an atypical oxidation state.) (a) NO₂^-(aq) + Cr₂O₇^2-(aq) → Cr³⁺(aq) + NO₃^-(aq) (acidic solution) (b) S(s) + HNO₃(aq) → H₂SO₃(aq) + N₂O(g) (acidic solution) (c) Cr₂O₇^2- (aq) + CH₃OH(aq) → HCOOH(aq) + Cr³⁺(aq) (acidic solution) (d) BrO₃^-(aq) + N₂H₄(g) → Br^-(aq) + N₂(g) (acidic solution)

문제 30

Complete and balance the following equations, and identify the oxidizing and reducing agents. (Recall that the O atoms in hydrogen peroxide, H2O2, have an atypical oxidation state.)

a. S(s) + HNO3(aq) → H2SO3(aq) + N2O(g) (acidic solution)

b. BrO3-(aq) + N2H4(g) → Br-(aq) + N2(g) (acidic solution)

c. H2O2(aq) + ClO2(aq) → ClO20(aq) _ O2(g) (basic solution)

문제 30c

Complete and balance the following equations, and identify the oxidizing and reducing agents. (Recall that the O atoms in hydrogen peroxide, H2O2, have an atypical oxidation state.) H2O21aq2 + ClO21aq2 ¡ ClO2-1aq2 + O21g2 (basic solution)

문제 31

Indicate whether each statement is true or false: (a) The cathode is the electrode at which oxidation takes place. (b) A galvanic cell is another name for a voltaic cell. (c) Electrons flow spontaneously from anode to cathode in a voltaic cell.

문제 32c

Indicate whether each statement is true or false: (c) A salt bridge or permeable barrier is necessary to allow a voltaic cell to operate.

문제 33f

A voltaic cell similar to that shown in Figure 20.5 is constructed. One electrode half-cell consists of a silver strip placed in a solution of AgNO3, and the other has an iron strip placed in a solution of FeCl2. The overall cell reaction is Fe1s2 + 2 Ag+1aq2 ¡ Fe2+1aq2 + 2 Ag1s2 (f) In which directions do the cations and anions migrate through the solution?

문제 35a

(a) What is the definition of the volt?

문제 35b

(b) Do all voltaic cells produce a positive cell potential?

문제 36

(a) Which electrode of a voltaic cell, the cathode or the anode, corresponds to the higher potential energy for the electrons? (b) What are the units for electrical potential? How does this unit relate to energy expressed in joules?

문제 37b

(b) Write the half-reaction that occurs at a hydrogen electrode in acidic aqueous solution when it serves as the anode of a voltaic cell.

문제 38c

문제 39

A voltaic cell that uses the reaction Tl3+(aq) + 2 Cr2+(aq) → Tl+(aq) + 2 Cr3+(aq) has a measured standard cell potential of +1.19 V. (c) Sketch the voltaic cell, label the anode and cathode, and indicate the direction of electron flow.

문제 40a

A voltaic cell that uses the reaction PdCl₄^2-(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.

문제 40b

A voltaic cell that uses the reaction PdCl₄^2-(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.

문제 40c

A voltaic cell that uses the reaction PdCl₄^2-(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

문제 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

문제 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

문제 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

문제 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

문제 42

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)

문제 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.