ch 19 multiple choice

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Mg(s) + Al3+(aq) → Al(s) + Mg2+(aq) A) 6 B) 2 C) 3 D) 1 E) 4

A) 6

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Fe(s) ∣ Fe3+(aq, 0.0011 M) Fe3+(aq, 2.33 M) ∣ Fe(s) A) +0.066 V B) -0.036 V C) 0.00 V D) -0.099 V E) +0.20 V

A) +0.066 V

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Sn(s) ∣ Sn2+(aq, 0.022 M) Ag+(aq, 2.7 M) ∣ Ag(s) A) +1.01 V B) -0.83 V C) +1.31 V D) +0.01 V E) -0.66 V

A) +1.01 V

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25°C. (The equation is balanced.) Pb(s) + Br2(l) → Pb2+(aq) + 2 Br⁻(aq) Pb2+(aq) + 2 e⁻ → Pb(s) E° = -0.13 V Br2(l) + 2 e⁻ → 2 Br⁻(aq) E° = +1.07 V A) +1.20 V B) +0.94 V C) -0.94 V D) -1.20 V E) -0.60 V

A) +1.20 V

Use the tabulated half-cell potentials to calculate ΔG° for the following redox reaction. 2 Al(s) + 3 Mg2+(aq) → 2 Al3+(aq) + 3 Mg(s) A) +4.1 x 102 kJ B) +1.4 x 102 kJ C) -2.3 x 102 kJ D) -7.8 x 102 kJ E) +6.8 x 102 kJ

A) +4.1 x 102 kJ

A galvanic cell consists of a Ni2+/ Ni half-cell and a standard hydrogen electrode. If the Ni2+/ Ni half-cell standard cell functions as the anode, and the standard cell potential is 0.26 V, what is the standard reduction potential for the Ni2+/ Ni half-cell? A) - 0.26 V B) - 0.13 V C) + 0.13 V D) + 0.26 V

A) - 0.26 V

What mass of silver can be plated onto an object in 33.5 minutes at 8.70 A of current? Ag⁺(aq) + e⁻ → Ag(s) A) 19.6 g B) 0.326 g C) 9.78 g D) 3.07 g E) 0.102 g

A) 19.6 g

What is the balanced chemical equation for the galvanic cell reaction expressed using shorthand notation below? Al(s) ∣ Al3+(aq) ∣∣ Fe2+(aq) ∣ Fe(s) A) 2 Al(s) + 3 Fe2+(aq) → 2 Al3+(aq) + 3 Fe(s) B) 3 Al(s) + 2 Fe2+(aq) → 3 Al3+(aq) + 2 Fe(s) C) 2 Fe(s) + 3 Al3+(aq) → 2 Fe2+(aq) + 3 Al(s) D) 3 Fe(s) + 2 Al3+(aq) → 3 Fe2+(aq) + 2 Al(s)

A) 2 Al(s) + 3 Fe2+(aq) → 2 Al3+(aq) + 3 Fe(s)

The standard cell potential (E°) of a voltaic cell constructed using the cell reaction below is 0.76 V: Zn (s) + 2H+ (aq) → Zn2+ (aq) + H2 (g) With PH2 = 1.0 atm and [Zn2+] = 1.0 M, the cell potential is 0.66 V. The concentration of H+ in the cathode compartment is __________ M. A) 2.0 × 10-2 B) 4.2 × 10-4 C) 1.4 × 10-1 D) 4.9 × 101 E) 1.0 × 10-12

A) 2.0 × 10-2

The town of Natrium, West Virginia, derives its name from the sodium produced in the electrolysis of molten sodium chloride (NaCl) mined from ancient salt deposits. The number of kilowatt-hours of electricity required to produce 4.60 kg of metallic sodium from the electrolysis of molten NaCl(s) is __________ when the applied emf is 4.50 V. A) 24.1 B) 0.0414 C) 0.0241 D) 48.3 E) 12.1

A) 24.1

How many grams of chromium metal are plated out when a constant current of 8.00 A is passed through an aqueous solution containing Cr3+ ions for 320. minutes? A) 27.6 g B) 49.2 g C) 82.4 g D) 248 g

A) 27.6 g

The gas OF2 can be produced from the electrolysis of an aqueous solution of KF, as shown in the equation below. OF2(g) + 2 H+(aq) + 4 e- → H2O(l) + 2 F-(aq) E° = +2.15 V Using the given standard reduction potential, calculate the amount of OF2 that is produced, and the electrode at which the OF2 is produced, upon the passage of 0. 480 faradays through an aqueous KF solution. A) 6.48 g of OF2 at the anode. B) 26.0 g of OF2 at the anode. C) 6.48 g of OF2 at the cathode. D) 26.0 g of OF2 at the cathode.

A) 6.48 g of OF2 at the anode.

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Al and F2 in the balanced reaction? Al(s) + F2(g)→ Al3+(aq) + F-(aq) A) Al = 2, F2 = 3 B) Al = 2, F2 = 6 C) Al = 1, F2 = 1 D) Al = 2, F2 = 1 E) Al = 3, F2 = 2

A) Al = 2, F2 = 3

What element is being oxidized in the following redox reaction? MnO4⁻ (aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g) A) C B) O C) Mn D) H

A) C

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cd and Ag+ in the balanced reaction? Cd(s) + Ag+(aq) → Ag(s) + Cd2+(aq) A) Cd = 1, Ag⁺ = 2 B) Cd = 1, Ag⁺ = 1 C) Cd = 2, Ag⁺ = 1 D) Cd = 2, Ag⁺ = 2 E) Cd = 3, Ag⁺ = 1

A) Cd = 1, Ag⁺ = 2

What element is being oxidized in the following redox reaction? Cr(OH)4⁻(aq) + ClO⁻(aq) → CrO42-(aq) + Cl⁻(aq) A) Cr B) O C) H D) Cl

A) Cr

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Cr(OH)4⁻ and ClO⁻ in the balanced reaction? Cr(OH)4⁻(aq) + ClO⁻(aq) → CrO42-(aq) + Cl⁻(aq) A) Cr(OH)4⁻ = 2, ClO⁻ = 3 B) Cr(OH)4⁻ = 1, ClO⁻ = 1 C) Cr(OH)4⁻ = 1, ClO⁻ = 2 D) Cr(OH)4⁻ = 2, ClO⁻ = 6 E) Cr(OH)4⁻ = 6, ClO⁻ = 5

A) Cr(OH)4⁻ = 2, ClO⁻ = 3

What is the reaction at the anode in a breathalyzer? A) Ethanol is oxidized to acetic acid. B) Acetic acid is reduced to ethanol. C) Oxygen is reduced. D) Hydrogen is oxidized. E) Ethanol is oxidized to acetaldehyde.

A) Ethanol is oxidized to acetic acid.

Using the following standard reduction potentials, Fe3+(aq) + e- →Fe2+(aq) E° = +0. 77 V Ni2+(aq) + 2 e- →Ni(s) E° = -0.23 V calculate the standard cell potential for the galvanic cell reaction given below, and determine whether or not this reaction is spontaneous under standard conditions. Ni2+(aq) + 2 Fe2+(aq) → 2 Fe3+(aq) + Ni(s) A) E° = - 1.00 V, nonspontaneous B) E° = - 1.00 V, spontaneous C) E° = + 1.00 V, nonspontaneous D) E° = + 1.00 V, spontaneous

A) E° = - 1.00 V, nonspontaneous

What is undergoing oxidation in the redox reaction represented by the following cell notation? Fe(s) ∣ Fe3+(aq) Cl2(g) ∣ Cl⁻(aq) ∣ Pt A) Fe(s) B) Fe3+(aq) C) Cl2(g) D) Cl⁻(aq) E) Pt

A) Fe(s)

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of H2C2O4 and H2O in the balanced reaction? MnO4⁻ (aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g) A) H2C2O4 = 5, H2O = 8 B) H2C2O4 = 1, H2O = 1 C) H2C2O4 = 5, H2O = 1 D) H2C2O4 = 1, H2O = 4 E) H2C2O4 = 3, H2O = 2

A) H2C2O4=5 , H2O=8

Which of the following is the strongest oxidizing agent? A) H2O2(aq) B) Fe3+(aq) C) ClO2(g) D) I2(s) E) Fe(s)

A) H2O2(aq)

Predict the species that will be reduced first if the following mixture of molten salts undergoes electrolysis. Na+, Ca2+, Cl⁻, Br⁻, F⁻ A) Na⁺ B) Cl⁻ C) Ca2+ D) Br⁻ E) F⁻

A) Na⁺

What is the reducing agent in the redox reaction represented by the following cell notation? Ni(s) ∣ Ni2+(aq) Ag+(aq) ∣ Ag(s) A) Ni(s) B) Ni2+(aq) C) Ag+(aq) D) Ag(s) E) Pt

A) Ni(s)

What is the shorthand notation that represents the following galvanic cell reaction? Pb(s) + Cu(NO3)2(aq) → Pb(NO3)2(aq) + Cu(s) A) Pb(s) ∣ Pb2+(aq) ∣∣ Cu2+(aq) ∣ Cu(s) B) Cu(s) ∣ Cu2+(aq) ∣∣ Pb2+(aq) ∣ Pb(s) C) Pb(s) ∣ NO3-(aq) ∣∣ NO3-(aq) ∣ Cu(s) D) Cu(s) ∣ Cu(NO3)2(aq) ∣∣ Pb(NO3)2(aq) ∣ Pb(s)

A) Pb(s) ∣ Pb2+(aq) ∣∣ Cu2+(aq) ∣ Cu(s)

What is the reducing agent in the redox reaction represented by the following cell notation? Sn(s) ∣ Sn2+(aq) Ag+(aq) ∣ Ag(s) A) Sn(s) B) Ag+(aq) C) Sn2+(aq) D) Ag(s) E) Pt

A) Sn(s)

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25°C. A) Sn4+(aq) + Mg(s) B) Cr3+(aq) + Ni(s) C) Zn(s) + Na+(aq) D) Fe(s) + Ba2+(aq) E) None of the above pairs will react.

A) Sn4+(aq) + Mg(s)

Identify the battery that is used as a common flashlight battery. A) dry-cell battery B) lithium ion battery C) lead-acid storage battery D) NiCad battery E) fuel cell

A) dry-cell battery

Identify the location of oxidation in an electrochemical cell. A) the anode B) the cathode C) the electrode D) the salt bridge E) the socket

A) the anode

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Cu(s) ∣ Cu2+(aq, 0.0032 M) Cu2+(aq, 4.48 M) ∣ Cu(s) A) 0.00 V B) +0.093 V C) +0.34 V D) +0.186 V E) +0.052 V

B) +0.093 V

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25°C. (The equation is balanced.) Sn(s) + 2 Ag⁺(aq) → Sn2+(aq) + 2 Ag(s) Sn2+(aq) + 2 e⁻ → Sn(s) E° = -0.14 V Ag⁺(aq) + e⁻ → Ag(s) E° = +0.80 V A) +1.74 V B) +0.94 V C) +1.08 V D) -1.08 V E) -1.74 V

B) +0.94 V

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Mg(s) ∣ Mg2+(aq, 2.74 M) Cu2+(aq, 0.0033 M) ∣ Cu(s) A) -2.80 V B) +2.62 V C) +2.71 V D) +2.12 V E) -1.94 V

B) +2.62 V

A voltaic cell is constructed with two silver-silver chloride electrodes, where the half-reaction is AgCl (s) + e- → Ag (s) + Cl- (aq) E° = +0.222 V The concentrations of chloride ion in the two compartments are 0.0222 M and 2.22 M, respectively. The cell emf is __________ V. A) 0.212 B) 0.118 C) 0.00222 D) 22.2 E) 0.232

B) 0.118

How many grams of nickel metal are plated out when a constant current of 15.0 A is passed through aqueous NiCl2 for 60.0 minutes? A) 10.9 g B) 16.4 g C) 32.8 g D) 36.3 g

B) 16.4 g

The standard emf for the cell using the overall cell reaction below is +2.20 V: 2 Al (s) + 3 I2 (s) → 2 Al3+ (aq) + 6 I- (aq) The emf generated by the cell when [Al3+] = 4.5 × 10-3 M and [I-] = 0.15 M is __________ V. A) 2.20 B) 2.32 C) 2.10 D) 2.39 E) 2.23

B) 2.32

What mass of aluminum can be plated onto an object in 755 minutes at 5.80 A of current? A) 73.5 g B) 24.5 g C) 220. g D) 147 g E) 8.17 g

B) 24.5 g

A galvanic cell consists of one half-cell that contains Ag(s) and Ag+(aq), and one half-cell that contains Cu(s) and Cu2+(aq). What species are produced at the electrodes under standard conditions? Ag+(aq) + e- → Ag(s) E° = +0.80 V Cu2+(aq) + 2 e- → Cu(s) E° = +0.34 V A) Ag(aq) is formed at the cathode and, Cu(s) is formed at the anode. B) Ag(s) is formed at the cathode, and Cu2+(aq) is formed at the anode. C) Cu(s) is formed at the cathode, and Ag+(aq) is formed at the anode. D) Cu2+(aq) is formed at the cathode, and Cu(s) is formed at the anode.

B) Ag(s) is formed at the cathode, and Cu2+(aq) is formed at the anode.

What is the oxidizing agent in the redox reaction represented by the following cell notation? Sn(s) ∣ Sn2+(aq) Ag+(aq) ∣ Ag(s) A) Sn(s) B) Ag+(aq) C) Sn2+(aq) D) Ag(s) E) Pt

B) Ag+(aq)

Which of the following is the strongest oxidizing agent? A) Br2(l) B) Au3+(aq) C) Ag(s) D) Br⁻(aq) E) Au(s)

B) Au3+(aq)

Which of the following is the weakest reducing agent? A) Br2(l) B) Au3+(aq) C) Ag(s) D) Br⁻(aq) E) Au(s)

B) Au3+(aq)

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25°C. A) I-(aq) + Zn2+(aq) B) Ca(s) + Mg2+(aq) C) H2(g) + Cd2+(aq) D) Ag(s) + Sn2+(aq) E) All of the above pairs will react.

B) Ca(s) + Mg2+(aq)

Given that E°red = -1.66 V for Al3+/ Al at 25°C, find E° and E for the concentration cell expressed using shorthand notation below. Al(s) ∣ Al3+(1.0 × 10-5 M) ∣∣ Al3+(0.100 M) ∣ Al(s) A) E° = 0.00 V and E = +0.24 V B) E° = 0.00 V and E = +0.12 V C) E° = -1.66 V and E = -1.42 V D) E° = -1.66 V and E = -1.54 V

B) E° = 0.00 V and E = +0.12 V

What is undergoing reduction in the redox reaction represented by the following cell notation? Pb(s) ∣ Pb2+(aq) H+(aq) ∣ H2(g) ∣ Pt A) H2(g) B) H+(aq) C) Pb2+(aq) D) Pb(s) E) Pt

B) H+(aq)

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of H⁺ and Fe3+ in the balanced reaction? Fe2+(aq) + MnO4⁻(aq) → Fe3+(aq) + Mn2+(aq) A) H⁺ = 2, Fe3+ = 3 B) H⁺ = 8, Fe3+ = 5 C) H⁺ = 3, Fe3+ = 2 D) H⁺ = 5, Fe3+ = 1 E) H⁺ = 8, Fe3+ = 1

B) H⁺ = 8, Fe3+ = 5

Consider the following standard reduction potentials, Ni2+(aq) + 2 e- → Ni(s) E° = - 0.26 V I2(s) + 2 e- → 2 I-(aq) E° = +0.54 V Under standard conditions, A) Ni2+(aq) is a stronger oxidizing agent than I2(s) and I-(aq) is a stronger reducing agent than Ni(s). B) I2(s) is a stronger oxidizing agent than Ni2+(aq) and Ni(s) is a stronger reducing agent than I-(aq). C) Ni(s) is a stronger oxidizing agent than I-(aq) and Ni2+(aq) is a stronger reducing agent than I2(s). D) I-(aq) is a stronger oxidizing agent than Ni(s) and I2(s) is a stronger reducing agent than Ni2+(aq).

B) I2(s) is a stronger oxidizing agent than Ni2+(aq) and Ni(s) is a stronger reducing agent than I-(aq).

Determine the redox reaction represented by the following cell notation. Mg(s) ∣ Mg2+(aq) Cu2+(aq) ∣ Cu(s) A) Cu(s) + Mg2+(aq) → Mg(s) + Cu2+(aq) B) Mg(s) + Cu2+(aq) → Cu(s) + Mg2+(aq) C) 2 Mg(s) + Cu2+(aq) → Cu(s) + 2 Mg2+(aq) D) 2 Cu(s) + Mg2+(aq) → Mg(s) + 2 Cu2+(aq) E) 3 Mg(s) + 2 Cu2+(aq) → 2 Cu(s) + 3 Mg2+(aq)

B) Mg(s) + Cu2+(aq) → Cu(s) + Mg2+(aq)

What element is being oxidized in the following redox reaction? Zn2+(aq) + NH4+(aq) → Zn(s) + NO3⁻(aq) A) Zn B) N C) H D) O

B) N

What is the balanced equation for the galvanic cell reaction expressed using shorthand notation below?. Ni(s) ∣ Ni2+(aq) ∣∣ Cl2(g) ∣ Cl-(aq) ∣ C(s) A) Ni(s) + 2 Cl-(aq) → Ni2+(aq) + Cl2(g) B) Ni(s) + Cl2(g) → Ni2+(aq) + 2 Cl-(aq) C) Ni2+(aq) + 2 Cl-(aq) → Ni(s) + Cl2(g) D) Ni2+(aq) + 2 Cl-(aq) → NiCl2(s)

B) Ni(s) + Cl2(g) → Ni2+(aq) + 2 Cl-(aq)

What element is being oxidized in the following redox reaction? H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g) A) H B) O C) Cl D) N E) C

B) O

Which of the following is the weakest reducing agent? A) Al(s) B) Zn(s) C) Mg(s) D) Al3+(aq) E) Mg2+(aq)

B) Zn(s)

Consider the galvanic cell, Zn(s) ∣ Zn2+(aq) ∣∣ Pb2+(aq) ∣ Pb(s). Which one of the following changes to the cell would cause the cell potential to increase (i.e., become more positive)? A) increase the [ Zn2+] concentration B) increase the [ Pb2+] concentration C) increase the mass of Zn(s) D) decrease the mass of Zn(s)

B) increase the [ Pb2+] concentration

Identify the location of reduction in an electrochemical cell. A) the anode B) the cathode C) the electrode D) the salt bridge E) the socket

B) the cathode

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Fe2+(aq) + K(s) → Fe(s) + K+(aq) A) 1 B) 2 C) 3 D) 4 E) 6

B)2

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25°C. (The equation is balanced.) Mg(s) + Cu2+(aq) → Cu(s) + Mg2+(aq) Mg2+(aq) + 2 e⁻ → Mg(s) E° = -2.38 V Cu2+(aq) + 2 e⁻ → Cu(s) E° = +0.34 V A) +2.04 V B) -2.04 V C) +2.72 V D) -1.36 V E) +1.36 V

C) +2.72 V

A voltaic cell is constructed with two Zn2+-Zn electrodes, where the half-reaction is Zn2+ + 2e- → Zn (s) E° = -0.763 V The concentrations of zinc ion in the two compartments are 5.50 M and 1.11 × 10-2 M, respectively. The cell emf is __________ V. A) -1.54 × 10-3 B) -378 C) 0.0798 D) 0.160 E) -0.761

C) 0.0798

The standard emf for the cell using the overall cell reaction below is +0.48 V: Zn (s) + Ni2+ (aq) → Zn2+ (aq) + Ni (s) The emf generated by the cell when [Ni2+] = 2.50 M and [Zn2+] = 0.100 M is __________ V. A) 0.40 B) 0.50 C) 0.52 D) 0.56 E) 0.44

C) 0.52

Use the tabulated half-cell potentials to calculate the equilibrium constant (K) for the following balanced redox reaction at 25°C. 2 Al(s) + 3 Mg2+(aq) → 2 Al3+(aq) + 3 Mg(s) A) 1.1 × 1072 B) 8.9 × 10-73 C) 1.1 x 10-72 D) 1.0 × 1024 E) 4.6 × 1031

C) 1.1 x 10-72

) Use the tabulated half-cell potentials to calculate the equilibrium constant (K) for the following balanced redox reaction at 25°C. 3 I2(s) + 2 Fe(s) → 2 Fe3+(aq) + 6 I⁻(aq) A) 3.5 × 10-59 B) 1.1 × 1017 C) 2.4 × 1058 D) 8.9 × 10-18 E) 1.7 × 1029

C) 2.4 × 1058

Nickel can be plated from aqueous solution according to the following half reaction. How long would it take (in min) to plate 29.6 g of nickel at 4.7 A? Ni2+(aq) + 2 e⁻ → Ni(s) A) 1.7 × 102 min B) 5.9 × 102 min C) 3.5 × 102 min D) 4.8 × 102 min E) 6.2 × 102 min

C) 3.5 × 102 min

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) I2(s) + Fe(s) → Fe3+(aq) + I⁻(aq) A) 1 B) 2 C) 6 D) 3 E) 4

C) 6

For a galvanic cell that uses the following two half-reactions, Cr2O72-(aq) + 14 H+(aq) + 6 e- → 2 Cr3+(aq) + 7 H2O(l) Pb(s) → Pb2+(aq) + 2 e- how many moles of Pb(s) are oxidized by three mol es of Cr2O72-? A) 3 B) 6 C) 9 D) 18

C) 9

Which of the following reactions would have the smallest value of K at 298 K? A) A + B → C; E°cell = +1.22 V B) A + 2 B → C; E°cell = +0.98 V C) A + B → 2 C; E°cell = -0.030 V D) A + B → 3 C; E°cell = +0.15 V E) More information is needed to determine.

C) A + B → 2 C; E°cell = -0.030 V

What is the oxidizing agent in the redox reaction represented by the following cell notation? Ni(s) ∣ Ni2+(aq) Ag+(aq) ∣ Ag(s) A) Ni(s) B) Ni2+(aq) C) Ag+(aq) D) Ag(s) E) Pt

C) Ag+(aq)

What element is being reduced in the following redox reaction? H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g) A) H B) O C) Cl D) N E) C

C) Cl

What is undergoing reduction in the redox reaction represented by the following cell notation? Fe(s) ∣ Fe3+(aq) Cl2(g) ∣ Cl⁻(aq) ∣ Pt A) Fe(s) B) Fe3+(aq) C) Cl2(g) D) Cl⁻(aq) E) Pt

C) Cl2(g)

What is the reduction half-reaction for the following overall galvanic cell reaction? Co2+(aq) + 2 Ag(s) → Co(s) + 2 Ag+(aq) A) Ag(s) + e- → Ag+(aq) B) Ag+(aq) + e- → Ag(s) C) Co2+(aq) + 2 e- → Co(s) D) Co2+(aq) + e- → Co(s)

C) Co2+(aq) + 2 e- → Co(s)

Which of the following metals will dissolve in nitric acid but not hydrochloric? A) Fe B) Pb C) Cu D) Sn E) Ni

C) Cu

Which of the following is the strongest reducing agent? A) Al(s) B) Zn(s) C) Mg(s) D) Al3+(aq) E) Mg2+(aq)

C) Mg(s)

What is the reaction at the cathode in a breathalyzer? A) Ethanol is oxidized to acetic acid. B) Acetic acid is reduced to ethanol. C) Oxygen is reduced. D) Hydrogen is oxidized. E) Ethanol is oxidized to acetaldehyde.

C) Oxygen is reduced.

Determine the cell notation for the redox reaction given below. Sn(s) + 2 Ag⁺(aq) → Sn2+(aq) + 2 Ag(s) A) Ag+(aq) ∣ Ag(s) Sn(s) ∣ Sn2+(aq) B) Ag(s) ∣ Ag+(aq) Sn2+(aq) ∣ Sn(s) C) Sn(s) ∣ Sn2+(aq) Ag+(aq) ∣ Ag(s) D) Sn2+(aq) ∣ Sn(s) Ag(s) ∣ Ag+(aq) E) Sn(s) ∣ Ag(s) Sn2+(aq) ∣ Ag+(aq)

C) Sn(s) ∣ Sn2+(aq) Ag+(aq) ∣ Ag(s)

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Zn and H+ in the balanced reaction? Zn2+(aq) + NH4+(aq) → Zn(s) + NO3⁻(aq) A) Zn = 1, H⁺ = 8 B) Zn = 1, H⁺ = 4 C) Zn = 4, H⁺ = 10 D) Zn = 2, H⁺ = 4 E) Zn = 3, H⁺ = 5

C) Zn = 4, H+=4

Describe how water can be a good conductor of current. A) use pure water B) heat the water C) add salt D) chill the water E) vaporize the water

C) add salt

Identify the components of a fuel cell. A) nickel-metal hydride B) lithium ion C) hydrogen-oxygen D) nickel-cadmium E) zinc-manganese

C) hydrogen-oxygen

Identify the battery that is in most automobiles. A) dry-cell battery B) lithium ion battery C) lead-acid storage battery D) NiCad battery E) fuel cell

C) lead-acid storage battery

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25°C. A) Pb2+(aq) + Cu(s) B) Ag+(aq) + Br⁻(aq) C) Li+(aq) + Al(s) D) Fe3+(aq) + Ni(s) E) None of the above pairs will react.

D) Fe3+(aq) + Ni(s)

Which of the following is the weakest oxidizing agent? A) H2O2(aq) B) Fe3+(aq) C) ClO2(g) D) I2(s) E) Fe(s)

D) I2(s)

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25 °C. (The equation is balanced.) 2 K(s) + I2(s) → 2 K⁺(aq) + 2 I⁻(aq) K+(aq) + e⁻ → K (s) E° = -2.93 V I2(s) + 2 e⁻ → 2 I⁻(aq) E° = +0.54 V A) +6.40 V B) +1.85 V C) -5.32 V D) +3.47 V E) +5.32 V

D) +3.47 V

Use the tabulated half-cell potentials to calculate ΔG° for the following balanced redox reaction. Pb2+(aq) + Cu(s) → Pb(s) + Cu2+(aq) A) -41 kJ B) -0.47 kJ C) +46 kJ D) +91 kJ E) -21 kJ

D) +91 kJ

Use the tabulated half-cell potentials to calculate the equilibrium constant (K) for the following balanced redox reaction at 25°C. Pb2+(aq) + Cu(s) → Pb(s) + Cu2+(aq) A) 7.9 × 10-8 B) 8.9 × 107 C) 7.9 × 1015 D) 1.3 × 10-16 E) 1.1 × 10-8

D) 1.3 × 10-16

The electrolysis of molten AlCl3 for 3.25 hr with an electrical current of 15.0 A produces __________ g of aluminum metal. A) 147 B) 0.606 C) 4.55 × 10-3 D) 16.4 E) 49.1

D) 16.4

How many kilowatt-hours of electricity are used to produce 3.00 kg of magnesium in the electrolysis of molten MgCl2 with an applied emf of 4.50 V? A) 0.0336 B) 0.0298 C) 7.4 D) 29.8 E) 14.9

D) 29.8

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 5.00 moles of copper metal? A) 0.187 hours B) 0.373 hours C) 2.68 hours D) 5.36 hours

D) 5.36 hours

Which of the following reactions would be the most spontaneous at 298 K? A) A + 2 B → C; E°cell = +0.98 V B) A + B → 2 C; E°cell = -0.030 V C) A + B → 3 C; E°cell = +0.15 V D) A + B → C; E°cell = +1.22 V E) More information is needed to determine.

D) A + B → C; E°cell = +1.22 V

Which of the following metals will dissolve in nitric acid but not hydrochloric? A) Cd B) Cr C) Mn D) Ag E) Al

D) Ag

Which of the following metals will not dissolve in nitric acid or hydrochloric acid? A) Zn B) Cu C) Ni D) Au E) all of the above

D) Au

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Br2 and OH⁻ in the balanced reaction? Br2(l) → BrO3⁻(aq) + Br⁻(aq) A) Br2 = 1, OH⁻ = 2 B) Br2 = 2, OH⁻ = 5 C) Br2 = 3, OH⁻ = 3 D) Br2 = 3, OH⁻ = 6 E) Br2 = 1, OH⁻ = 6

D) Br2 = 3, OH⁻ = 6

What element is being reduced in the following redox reaction? Cr(OH)4⁻(aq) + ClO⁻(aq) → CrO42-(aq) + Cl⁻(aq) A) Cr B) O C) H D) Cl

D) Cl

Which of the following is the strongest reducing agent? A) Sn2+(aq) B) Cr3+(aq) C) Sn4+(aq) D) Cr(s) E) Sn(s)

D) Cr (s)

Which of the following is the weakest oxidizing agent? A) Sn2+(aq) B) Cr3+(aq) C) Sn4+(aq) D) Cr(s) E) Sn(s)

D) Cr (s)

What statement is NOT true about standard electrode potentials? A) E°cell is positive for spontaneous reactions. B) Electrons will flow from more negative electrode to more positive electrode. C) The electrode potential of the standard hydrogen electrode is exactly zero. D) E°cell is the difference in voltage between the anode and the cathode. E) The electrode in any half-cell with a greater tendency to undergo reduction is positively charged relative to the standard hydrogen electrode and therefore has a positive E°.

D) E°cell is the difference in voltage between the anode and the cathode.

Based on the following information, Cl2(g) + 2 e- → 2 Cl-(aq) E° = + 1.36 V Mg2+(aq) + 2 e- → 2 Mg(s) E° = -2.37 V which of the following chemical species is the strongest reducing agent? A) Cl2(g) B) Mg2+(aq) C) Cl-(aq) D) Mg(s)

D) Mg(s)

For the galvanic cell reaction, expressed below using shorthand notation, what half-reaction occurs at the cathode? Zn(s) ∣ Zn2+(aq) ∣∣ Ni2+(aq) ∣ Ni(s) A) Zn(s) → Zn2+(aq) + 2 e- B) Zn2+(aq) + 2 e- → Zn(s) C) Ni(s) → Ni2+(aq) + 2 e- D) Ni2+(aq) + 2 e- → Ni(s)

D) Ni2+(aq) + 2 e- → Ni(s)

What is undergoing oxidation in the redox reaction represented by the following cell notation? Pb(s) ∣ Pb2+(aq) H+(aq) ∣ H2(g) ∣ Pt A) H2(g) B) H+(aq) C) Pb2+(aq) D) Pb(s) E) Pt

D) Pb(s)

Determine the cell notation for the redox reaction given below. Pb(s) + 2 H⁺(aq) → Pb2+(aq) + H2(g) A) H+(aq) ∣ H2(g) ∣ Pt Pb(s) ∣ Pb2+(aq) B) H2(g) ∣ H+(aq) ∣ Pt Pb2+(aq) ∣ Pb(s) C) Pb2+(aq) ∣ Pb(s) H2(g) ∣ H+(aq) ∣ Pt D) Pb(s) ∣ Pb2+(aq) H+(aq) ∣ H2(g) ∣ Pt E) Pb(s) ∣ H2(g) Pb2+(aq) ∣ H+(aq) ∣ Pt

D) Pb(s) ∣ Pb2+(aq) H+(aq) ∣ H2(g) ∣ Pt

What is the shorthand notation that represents the following galvanic cell reaction? 2 Fe2+(aq) + F2(g) → 2 Fe3+(aq) + 2 F-(aq) A) Fe2+(aq) ∣ Fe3+(aq) ∣∣ F2(g) ∣ F-(aq) B) Fe(s) ∣ Fe2+(aq) ∣∣ Fe3+(aq) F2(g) ∣ F-(aq) ∣ C(s) C) Pt(s) ∣ Fe3+(aq), Fe2+(aq), F2(g) ∣∣ F-(aq) ∣ C(s) D) Pt(s) ∣ Fe2+(aq), Fe3+(aq) ∣∣ F2(g) ∣ F-(aq) ∣ C(s)

D) Pt(s) ∣ Fe2+(aq), Fe3+(aq) ∣∣ F2(g) ∣ F-(aq) ∣ C(s)

Identify a component in the formation of rust. A) salt B) moisture C) acid D) all of the above E) none of the above

D) all of the above

Identify the characteristics of a spontaneous reaction. A) ΔG° < 0 B) ΔE°cell > 0 C) K > 1 D) all of the above E) none of the above

D) all of the above

Identify the battery type that has a high overcharge tolerance. A) NiCad B) Li ion C) NiMH D) lead storage E) none of the above

D) lead storage

Predict the species that will be reduced first if the following mixture of molten salts undergoes electrolysis. Zn2+, Fe3+, Mg2+, Br-, I- A) Zn2+ B) Mg2+ C) Br- D) Fe3+ E) I-

D)Fe3+

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Al(s) ∣ Al3+(aq, 0.115 M) Al3+(aq, 3.89 M) ∣ Al(s) A) +1.66 V B) +0.060 V C) 0.00 V D) +0.090 V E) +0.030 V

E) +0.030 V

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Sn(s) ∣ Sn2+(aq, 1.8 M) Ag+(aq, 0.055 M) ∣ Ag(s) A) -0.94 V B) -0.85 V C) +1.02 V D) +0.98 V E) +0.86 V

E) +0.86 V

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25°C. (The equation is balanced.) 3 Cl2(g) + 2 Fe(s) → 6 Cl⁻(aq) + 2 Fe3+(aq) Cl2(g) + 2 e⁻ → 2 Cl⁻(aq) E° = +1.36 V Fe3+(aq) + 3 e⁻ → Fe(s) E° = -0.04 V A) +4.16 V B) -1.40 V C) -1.32 V D) +1.32 V E) +1.40 V

E) +1.40 V

Use the tabulated half-cell potentials to calculate ΔG° for the following balanced redox reaction. 3 I2(s) + 2 Fe(s) → 2 Fe3+(aq) + 6 I⁻(aq) A) -1.1 x 102 kJ B) +4.9 x 101 kJ C) -9.7 x 101 kJ D) +2.3 x 102 kJ E) -3.3 x 102 kJ

E) -3.3 x 102 kJ

How many seconds are required to produce 4.00 g of aluminum metal from the electrolysis of molten AlCl3 with an electrical current of 12.0 A? A) 27.0 B) 9.00 C) 1.19 × 103 D) 2.90 × 105 E) 3.57 × 103

E) 3.57 × 103

The most useful ore of aluminum is bauxite, in which Al is present as hydrated oxides, Al2O3 · xH2O. The number of kilowatt-hours of electricity required to produce 4.00 kg of aluminum from electrolysis of compounds from bauxite is __________ when the applied emf is 5.00 V. A) 0.0168 B) 0.0596 C) 39.7 D) 19.9 E) 59.6

E) 59.6

Define a salt bridge. A) A pathway, composed of salt water, that ions pass through. B) A pathway in which no ions flow. C) A pathway between the cathode and anode in which ions are reduced. D) A pathway between the cathode and anode in which ions are oxidized. E) A pathway by which counterions can flow between the half-cells without the solutions in the half-cell totally mixing.

E) A pathway by which counterions can flow between the half-cells without the solutions in the half-cell totally mixing.

Predict the species that will be oxidized first if the following mixture of molten salts undergoes electrolysis. Cu2+, Mg2+, Cl⁻, Br⁻, F⁻ A) Cl⁻ B) F⁻ C) Cu2+ D) Mg2+ E) Br⁻

E) Br⁻

) Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of ClO2 and H2O in the balanced reaction? H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g) A) ClO2 = 1, H2O = 1 B) ClO2 = 1, H2O = 2 C) ClO2 = 4, H2O = 3 D) ClO2 = 4, H2O = 2 E) ClO2 = 2, H2O = 2

E) ClO2 = 2, H2O = 2

Determine the cell notation for the redox reaction given below. 3 Cl2(g) + 2 Fe(s) → 6 Cl⁻(aq) + 2 Fe3+(aq) A) Cl2(g) ∣ Cl⁻(aq) ∣ Pt Fe(s) ∣ Fe3+(aq) B) Cl⁻(aq) ∣ Cl2(g) ∣ Pt Fe3+(aq) ∣ Fe(s) C) Fe3+(aq) ∣ Fe(s) Cl⁻(aq) ∣ Cl2(g) ∣ Pt D) Fe(s) ∣ Cl2(g) Fe3+(aq) ∣ Cl⁻(aq) ∣ Pt E) Fe(s) ∣ Fe3+(aq) Cl2(g) ∣ Cl⁻(aq) ∣ Pt

E) Fe(s) ∣ Fe3+(aq) Cl2(g) ∣ Cl⁻(aq) ∣ Pt

Which of the following is the strongest reducing agent? A) Na(s) B) Li+(aq) C) Ca(s) D) Ca2+(aq) E) Li(s)

E) Li(s)

Which of the following is the strongest oxidizing agent? A) MnO2(s) B) Cl⁻(aq) C) Cu⁺(aq) D) SO42-(aq) E) MnO4⁻(aq)

E) MnO4⁻(aq)

Which of the following metals will dissolve in HCl? A) Ba B) Na C) Mg D) Al E) all of the above

E) all of the above

Which of the following metals will not dissolve in nitric acid or hydrochloric acid? A) Al B) Fe C) Ag D) Na E) none of the above

E) none of the above

If Ecell > 0, what is Q and K?

Q<K

If Ecell = E°cell, what is Q?

Q=1

If Ecell = 0, what is Q and K?

Q=K

If E°cell < 0, what is Q and relation to K?

Q>K

What element is being reduced in the following redox reaction? MnO4⁻ (aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g) A) C B) O C) Mn D) H

c) Mn

Identify oxidation. a) increase in oxidation number b) loss of electrons c) gain of electrons d) decrease in oxidation number e) both A and B

e) both a and b

If E°cell > 0, what is ΔG°

ΔG° < 0

If E°cell < 0, what is ΔG°

ΔG° > 0