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문제 21a
At 900 °C, titanium tetrachloride vapor reacts with molten magnesium metal to form solid titanium metal and molten magnesium chloride. (a) Write a balanced equation for this reaction.
문제 21c
At 900 °C, titanium tetrachloride vapor reacts with molten magnesium metal to form solid titanium metal and molten magnesium chloride (c) Which substance is the reductant, and which is the oxidant?
문제 22a
Hydrazine (N2H4) and dinitrogen tetroxide (N2O4) form a self-igniting mixture that has been used as a rocket propellant. The reaction products are N2 and H2O. (a) Write a balanced chemical equation for this reaction.
문제 22c
Hydrazine (N2H4) and dinitrogen tetroxide (N2O4) form a self-igniting mixture that has been used as a rocket propellant. The reaction products are N2 and H2O. (c) Which substance serves as the reducing agent and which as the oxidizing agent?
문제 23a,b,c,d
Complete and balance the following half-reactions. In each case, indicate whether the half-reaction is an oxidation or a reduction. (a) Sn2+(aq) → Sn4+(aq) (acidic solution) (b) TiO2(s) → Ti2+(aq) (acidic solution) (c) ClO3-(aq) → Cl-(aq) (acidic solution) (d) N2(g) → NH4+(aq) (acidic solution)
문제 23f
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 24a,b,c,d
Complete and balance the following half-reactions. In each case indicate whether the half-reaction is an oxidation or a reduction. (a) Mo3+(aq) → Mo(s) (acidic solution) (b) H2SO3(aq) → SO42-(aq) (acidic solution) (c) NO3-(aq) → NO(g) (acidic solution) (d) O2(g) → H2O(l) (acidic solution)
문제 24g
Complete and balance the following half-reactions. In each case indicate whether the half-reaction is an oxidation or a reduction. (g) Cr(OH)3(s) → CrO42-(aq) (basic solution)
문제 25a,b,c
Complete and balance the following equations, and identify the oxidizing and reducing agents: (a) Cr2O72-(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 25d
Complete and balance the following equations, and identify the oxidizing and reducing agents: As2O3(s) + NO3-(aq) → H3AsO4(aq) + N2O3(aq) (acidic solution)
문제 25e
Complete and balance the following equations, and identify the oxidizing and reducing agents: MnO4-(aq) + Br-(aq) → MnO2(s) + BrO3-(aq) (basic solution)
문제 26a,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) + Cr2O72-(aq) → Cr3+(aq) + NO3-(aq) (acidic solution) (b) S(s) + HNO3(aq) → H2SO3(aq) + N2O(g) (acidic solution) (c) Cr2O72- (aq) + CH3OH(aq) → HCOOH(aq) + Cr3+(aq) (acidic solution) (d) BrO3-(aq) + N2H4(g) → Br-(aq) + N2(g) (acidic solution)
문제 26f
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)
- 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 27
- Indicate whether each statement is true or false: (a) The anode is the electrode at which oxidation takes place. (b) A voltaic cell always has a positive emf.
문제 28
문제 28c
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 29f
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 31a
(a) What is the definition of the volt?
문제 31b
(b) Do all voltaic cells produce a positive cell potential?
- (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 32
- (a) Write the half-reaction that occurs at a hydrogen electrode in acidic aqueous solution when it serves as the cathode of a voltaic cell. (b) What is standard about the standard hydrogen electrode?
문제 33
문제 33b
(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.
- What conditions must be met for a reduction potential to be considered a standard reduction potential?
문제 34
문제 34c
(c) Why is it impossible to measure the standard reduction potential of a single half-reaction?
- 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 35
문제 36a
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.
문제 36b
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.
문제 36c
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
문제 37a
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 37b
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