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Q:
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
Q:
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
Q:
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 VUsing 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.
Q:
Calculate the value of the reaction quotient, Q, for the galvanic cell expressed using shorthand notation below. Use the balanced chemical equation that has the smallest whole number stoichiometric coefficients.A) 132B) 115C) 8.70 10-3D) 7.56 10-3
Q:
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)
Q:
Using the following standard reduction potentials,Fe3+(aq) + e- -> Fe2+(aq) E = +0. 77 VNi2+(aq) + 2 e- -> Ni(s) E = -0.26 Vcalculate the standard cell potential for the 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 = - 1.03 V, nonspontaneousB) E = - 1.03 V, spontaneousC) E = + 1.03, nonspontaneousD) E = + 1.03, spontaneous
Q:
Based on the following information,Cl2(g) + 2 e- -> 2 Cl-(aq) E = + 1.36 VMg2+(aq) + 2 e- -> 2 Mg(s) E = -2.37 Vwhich of the following chemical species is the strongest reducing agent?A) Cl2(g)B) Mg2+(aq)C) Cl-(aq)D) Mg(s)
Q:
Consider the following standard reduction potentials,Ni2+(aq) + 2 e- -> Ni(s) E = - 0.26 VI2(s) + 2 e- -> 2 I-(aq) E = +0.54 VUnder 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).
Q:
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 VCu2+(aq) + 2 e- -> Cu(s) E = +0.34 VA) 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.
Q:
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
Q:
What is the balanced equation for the galvanic cell reaction expressed using shorthand notation below?
Q:
What is the balanced chemical equation for the galvanic cell reaction expressed using shorthand notation below?
Q:
For the galvanic cell reaction, expressed below using shorthand notation, what half-reaction occurs at the cathode?
Q:
What is the shorthand notation that represents the following galvanic cell reaction?
Q:
What is the shorthand notation that represents the following galvanic cell reaction?
Q:
What is the reduction half-reaction for the following overall 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)
Q:
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) 3B) 6C) 9D) 18
Q:
Determine the direction of electron flow and the direction of ion flow.
A) Electrons flow from a to c; K+ ions flow toward a and Cl- ions flow toward c.
B) Electrons flow from a to c; Cl- ions flow toward a and K+ ions flow toward c.
C) Electrons flow from c to a; K+ ions flow toward a and Cl- ions flow toward c.
D) Electrons flow from c to a; Cl- ions flow toward a and K+ ions flow toward c.
Q:
Determine whether this is a galvanic or an electrolytic cell and give the reaction occurring at the anode and the reaction occurring at the cathode.A) Electrolytic cellAnode reaction: K(s) -> K+(l) + e-Cathode reaction: Cl2(g) + 2e- -> 2 Cl-(l)B) Electrolytic cellAnode reaction: 2 Cl-(l) -> Cl2(g) + 2e-Cathode reaction: K+(l) + e- -> K(s)C) Galvanic cellAnode reaction: K(s) -> K+(l) + e-Cathode reaction: Cl2(g) + 2e- -> 2 Cl-(l)D) Galvanic cellAnode reaction: K(s) -> K+(l) + e-Cathode reaction: Cl2(g) + 2e- -> 2 Cl-(l)
Q:
Is the cell shown above a galvanic or an electrolytic cell? What is the direction of ion flow?
A) Electrolytic cell; Cu2+ ions flow toward electrode x and SO42- ions flow toward electrode y.
B) Electrolytic cell; Cu2+ ions flow toward electrode y and SO42- ions flow toward electrode x.
C) Galvanic cell; Cu2+ ions flow toward electrode x and SO42- ions flow toward electrode y.
D) Galvanic cell; Cu2+ ions flow toward electrode y and SO42- ions flow toward electrode x.
Q:
Is the cell shown above a galvanic or an electrolytic cell? Which is the anode and which is the cathode?
A) Electrolytic cell; electrode x is the anode and electrode y is the cathode.
B) Electrolytic cell; electrode y is the anode and electrode x is the cathode.
C) Galvanic cell; electrode x is the anode and electrode y is the cathode.
D) Galvanic cell; electrode y is the anode and electrode x is the cathode.
Q:
What is the quantitative change in the cell voltage on increasing the ion concentration in the cathode compartment by a factor of 10?
A) +0.03 V
B) +0.02 V
C) -0.02 V
D) -0.03 V
Q:
What is the quantitative change in the cell voltage on increasing the ion concentration in the anode compartment by a factor of 10?
A) +0.03 V
B) +0.02 V
C) -0.02 V
D) -0.03 V
Q:
What is the quantitative change in the cell voltage on increasing the ion concentration in the cathode compartment by a factor of 10?
A) +0.06 V
B) +0.03 V
C) -0.03 V
D) -0.06 V
Q:
What is the quantitative change in the cell voltage on increasing the ion concentration in the anode compartment by a factor of 10?
A) +0.06 V
B) +0.03 V
C) -0.03 V
D) -0.06 V
Q:
The initial concentrations of Ag+(aq) and Cu2+(aq) are both 1.0 M. What will happen to the cell voltage if 5.0 M AgNO3 is added to the compartment containing the 1.0 M Ag+(aq)? The cell voltage will
A) decrease.
B) increase.
C) remain the same.
D) can't tell from the information given
Q:
The initial concentrations of Ag+(aq) and Cu2+(aq) are both 1.0 M. What will happen to the cell voltage if 1.0 M Cu(NO3)2 is added to the compartment containing the 1.0 M Cu2+(aq)? The cell voltage will
A) decrease.
B) increase.
C) remain the same.
D) can't tell from the information given
Q:
The initial concentrations of Ag+(aq) and Cu2+(aq) are both 1.0 M. What will happen to the cell voltage if 5.0 M Cu(NO3)2 is added to the compartment containing the 1.0 M Cu2+(aq)? The cell voltage will
A) decrease.
B) increase.
C) remain the same.
D) can't tell from the information given
Q:
If the concentrations of Ag+(aq) and Cu2+(aq) are varied in this galvanic cell, which of the following four cells has the largest cell potential?
A) [Ag+] = 0.10 M and [Cu2+] = 0.10 M
B) [Ag+] = 1.0 M and [Cu2+] = 0.10 M
C) [Ag+] = 0.10 M and [Cu2+] = 1.0 M
D) [Ag+] = 1.0 M and [Cu2+] = 1.0 M
Q:
Given the half-cell potentials below, calculate the cell potential.Ag+(aq) + e- -> Ag(s) 0.80 VCu2+(aq) + 2 e- -> Cu(s) 0.34 VA) 0.46 VB) 1.14 VC) 1.26 VD) 1.94 V
Q:
What is the shorthand notation for this cell?
Q:
Identify the anode and cathode half-reactions and categorize each as either oxidation or reduction.A) Anode reaction: Ag+(aq) + e- -> Ag(s) (oxidation)Cathode reaction: Cu(s) -> Cu2+(aq) + 2e- (reduction)B) Anode reaction: Ag+(aq) + e- -> Ag(s) (reduction)Cathode reaction: Cu(s) -> Cu2+(aq) + 2e- (oxidation)C) Anode reaction: Cu(s) -> Cu2+(aq) + 2e- (oxidation)Cathode reaction: Ag+(aq) + e- -> Ag(s) (reduction)D) Anode reaction: Cu(s) -> Cu2+(aq) + 2e- (reduction)Cathode reaction: Ag+(aq) + e- -> Ag(s) (oxidation)
Q:
NaNO3(aq) is employed in the salt bridge. Give the direction of electron flow and the direction of ion flow from the salt bridge.
A) Electrons flow from a to c; Na+ flows into b and NO3- flows into d.
B) Electrons flow from a to c; NO3- flows into b and Na+ flows into d.
C) Electrons flow from c to a; Na+ flows into b and NO3- flows into d.
D) Electrons flow from c to a; NO3- flows into b and Na+ flows into d.
Q:
Identify and give the sign of each electrode.
A) a is Ag and (+), c is Cu and (-).
B) a is Ag and (-), c is Cu and (+).
C) a is Cu and (+), c is Ag and (-).
D) a is Cu and (-), c is Ag and (+).
Q:
Identify the electrodes and the direction of electron flow.
A) a is Ag, c is Cu and electrons flow from a to c.
B) a is Ag, c is Cu and electrons flow from c to a.
C) a is Cu, c is Ag and electrons flow from a to c.
D) a is Cu, c is Ag and electrons flow from c to a.
Q:
What is the shorthand notation for the cell?
A) Fe(s) | Fe2+(aq) || Sn(s) | Sn2+(aq)
B) Fe(s) | Fe2+(aq) || Sn2+(aq) | Sn(s)
C) Sn(s) | Sn2+(aq) || Fe(s) | Fe2+(aq)
D) Sn(s) | Sn2+(aq) || Fe2+(aq) | Fe(s)
Q:
What is the balanced equation for the cell reaction?A) Fe(s) + Sn(s) -> Fe2+(aq) + Sn2+(aq)B) Fe2+(aq) + Sn2+(aq) -> Fe(s) + Sn(s)C) Fe(s) + Sn2+(aq) -> Fe2+(aq) + Sn(s)D) Fe2+(aq) + Sn(s) -> Fe(s) + Sn2+(aq)
Q:
Identify the anode and cathode, and indicate the direction of ion flow to and from each electrode.
A) Fe is the anode and Sn is the cathode; Fe2+ ions flow to the anode and Sn2+ ions flow from the cathode.
B) Fe is the anode and Sn is the cathode; Sn2+ ions flow to the cathode and Fe2+ ions flow from the anode.
C) Sn is the anode and Al is the cathode; Fe2+ ions flow to the cathode and Sn2+ ions flow from the anode.
D) Sn is the anode and Al is the cathode; Sn2+ ions flow to the anode and Fe2+ ions flow from the cathode.
Q:
Identify the anode and cathode, and indicate the direction of Na+ ion and NO3- ion flow from the salt bridge.
A) Fe is the anode and Sn is the cathode; Na+ ions flow into half-cell compartment (A) and NO3- ions flow into half-cell compartment (B).
B) Fe is the anode and Sn is the cathode; NO3- ions flow into half-cell compartment (A) and Na+ ions flow into half-cell compartment (B).
C) Sn is the anode and Fe is the cathode; Na+ ions flow into half-cell compartment (A) and NO3- ions flow into half-cell compartment (B).
D) Sn is the anode and Fe is the cathode; NO3- ions flow into half-cell compartment (A) and Na+ ions flow into half-cell compartment (B).
Q:
What is the shorthand notation for the cell?
A) Al(s) | Al3+(aq) || Co(s) | Co2+(aq)
B) Al(s) | Al3+(aq) || Co2+(aq) | Co(s)
C) Co(s) | Co2+(aq) || Al(s) | Al3+(aq)
D) Co(s) | Co2+(aq) || Al3+(aq)| Al(s)
Q:
What is the balanced equation for the cell reaction?A) 2 Al(s) + 3 Co(s) -> 2 Al3+(aq) + 3 Co2+(aq)B) 2 Al3+(aq) + 3 Co2+(aq) -> 2 Al(s) + 3 Co(s)C) 2 Al(s) + 3 Co2+(aq) -> 2 Al3+(aq) + 3 Co(s)D) 2 Al3+(aq) + 3 Co(s) -> 2 Al(s) + 3 Co2+(aq)
Q:
Identify the anode and cathode, and indicate the direction of ion flow to and from each electrode.
A) Al is the anode and Co is the cathode; Al3+ ions flow to the anode and Co2+ ions flow from the cathode.
B) Al is the anode and Co is the cathode; Co2+ ions flow to the cathode and Al3+ ions flow from the anode.
C) Co is the anode and Al is the cathode; Al3+ ions flow to the cathode and Co2+ ions flow from the anode.
D) Co is the anode and Al is the cathode; Co2+ ions flow to the anode and Al3+ ions flow from the cathode.
Q:
Identify the anode and cathode, and indicate the direction of Na+ ion and NO3- ion flow from the salt bridge.
A) Al is the anode and Co is the cathode; Na+ ions flow into half-cell compartment (A) and NO3- ions flow into half-cell compartment (B).
B) Al is the anode and Co is the cathode; NO3- ions flow into half-cell compartment (A) and Na+ ions flow into half-cell compartment (B).
C) Co is the anode and Al is the cathode; Na+ ions flow into half-cell compartment (A) and NO3- ions flow into half-cell compartment (B).
D) Co is the anode and Al is the cathode; NO3- ions flow into half-cell compartment (A) and Na+ ions flow into half-cell compartment (B).
Q:
The cell reaction 2 Fe3+(aq) + Zn(s) -> Zn2+(aq) + 2 Fe2+(aq) occurs in the galvanic cell shown above. Which would be the most appropriate choices for the solidelectrode in half-cell (A) and in half-cell (B)?A) Fe(s) for half-cell (A) and Zn(s) for half-cell (B)B) Pt(s) for half-cell (A) and Zn(s) for half-cell (B)C) Fe(s) for half-cell (A) and Fe(s) for half-cell (B)D) Zn(s) for half-cell (A) and Pt(s) for half-cell (B)
Q:
The cell reaction 2 Fe3+(aq) + Zn(s) -> Zn2+(aq) + 2 Fe2+(aq) occurs in the galvanic cell shown above. Where should the Fe3+(aq) and Fe2+(aq) be found?A) Half-cell (A) contains Fe3+(aq) and half-cell (B) contains Fe2+(aq).B) Half-cell (A) contains Fe2+(aq) and half-cell (B) contains Fe3+(aq).C) Half-cell (A) contains Fe3+(aq) and Fe2+(aq).D) Half-cell (B) contains Fe3+(aq) and Fe2+(aq).
Q:
For the galvanic cell shown above, in what direction should the anions and cations in half-cell A move?
A) The anions tend to move to the solid electrode and the cations into the salt bridge.
B) The anions tend to move into the salt bridge and the cations toward the solid electrode.
C) The anions tend to move toward the solid electrode and the cations should not move.
D) The cations tend to move toward the solid electrode and the anions should not move.
Q:
The bright colors of anodized titanium are due to
A) electrodeposition of organic dyes on the titanium surface.
B) the formation of a titanium alloy with chromium and copper.
C) iridescence involving the semitransparent outer layer of TiO2.
D) trapping of organic dye molecules in a spongy TiO2 matrix.
Q:
The bright colors of anodized aluminum are due to
A) electrodeposition of organic dyes on the aluminum surface.
B) the formation of an aluminum alloy with chromium and copper.
C) iridescence involving the semitransparent outer layer of Al2O3.
D) trapping of organic dye molecules in a spongy Al2O3 matrix.
Q:
A constant current is passed through a solution containing Cu2+(aq) resulting in the deposition of 4.40 g of Cu at the cathode. Assuming a current efficiency of 100%, if this same current is passed through a solution of TcO4" for the same amount of time, how many grams of Tc would form at the cathode?
A) 0.969 g
B) 1.94 g
C) 6.78 g
D) 13.6 g
Q:
Chromium can be electroplated from an aqueous solution containing sulfuric acid and chromic acid, H2CrO4. What current is required to deposit chromium at a rate of 1.25 g/min?
A) 38.1 A
B) 38.7 A
C) 116 A
D) 232 A
Q:
How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 3.00 moles of copper metal?
A) 0.311 hours
B) 0.621 hours
C) 1.61 hours
D) 3.22 hours
Q:
How many grams of nickel metal are plated out when a constant current of 15.0 A is passed through aqueous NiCl2 for 80.0 minutes?
A) 14.7 g
B) 21.9 g
C) 43.8 g
D) 48.4 g
Q:
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 40.0 minutes?
A) 3.45 g
B) 6.15 g
C) 10.3 g
D) 31.0 g
Q:
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 VUsing 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 0.240 faradays through an aqueous KF solution.A) 3.24 g of OF2 at the anodeB) 13.0 g of OF2 at the anodeC) 3.24 g of OF2 at the cathodeD) 13.0 g of OF2 at the cathode
Q:
Which of the following statements concerning the electrorefining of copper in not true?
A) The anode is constructed of chalcocite, Cu2S.
B) The anode mud is a valuable source of silver, gold, and platinum.
C) Copper is oxidized at the anode and copper(II) ions are reduced at the cathode.
D) The process is used to purify copper.
Q:
Which requires the most electricity (in terms of faradays of charge transferred) per gram of useful product formed?
A) electrolysis of aqueous NaCl (chlor-alkali industry)
B) electrolysis of molten NaCl/CaCl2 in a Downs cell
C) electrorefining copper metal
D) production of aluminum in the Hall-Heroult process
Q:
The Hall-Heroult process for the production of aluminum involves the electrolysis of
A) an aqueous solution of Al(NO3)3.
B) molten Al2O3.
C) molten cryolite, Na3AlF6.
D) a molten mixture of Al2O3 and Na3AlF6.
Q:
The chlor-alkali industry is based on the electrolysis of aqueous NaCl. What are the products of this electrolysis?
A) Na and Cl2
B) NaOH, H2, and O2
C) NaOH, H2, and Cl2
D) NaOH, O2, and Cl2
Q:
O2(g) + 4 H+(aq) + 4 e- -> 2 H2O(l) E = +1.23 VPb2+(aq) + 2 e- -> Pb(s) E = -0.13 V2 H2O(l) + 2 e- -> H2(g) + 2 OH-(aq) E = -0.83 VBased on the half-reactions above, electrolysis of an aqueous solution of Pb(NO3)2 is expected to produce.A) Pb at the cathode and H2 at the anode.B) Pb at the cathode and O2 at the anode.C) H2 at the cathode and Pb at the anode.D) O2 at the cathode and Pb at the anode.
Q:
O2(g) + 4 H+(aq) + 4 e- -> 2 H2O(l) E = +1.23 VI2(s) + 2 e- -> 2 I-(aq) E = +0.54 V2 H2O(l) + 2 e- -> H2(g) + 2 OH-(aq) E = -0.83 VMg2+(aq) + 2 e- -> Mg(s) E = -2.37 VBased on the data above, electrolysis of an aqueous solution of MgI2, with inert electrodes, is expected to produceA) Mg at the cathode and I2 at the anode.B) H2 at the cathode and I2 at the anode.C) Mg at the cathode and O2 at the anode.D) H2 at the cathode and O2 at the anode.
Q:
Which statement concerning overvoltage is false?
A) Overvoltage is the additional voltage above the calculated voltage required to bring about electrolysis.
B) Overvoltage is often due to a high activation energy for the reaction at one electrode.
C) Overvoltage is small for half-reactions involving the formation of O2(g) or H2(g).
D) Overvoltage must be experimentally determined.
Q:
Which statement is true?
A) The cathode is positive for a galvanic cell and negative for an electrolytic cell.
B) Electrons flow through the external circuit to the cathode in a galvanic cell and to the anode in an electrolytic cell.
C) Oxidation occurs at the anode in a galvanic cell and at the cathode in an electrolytic cell.
D) Oxidation occurs at the cathode in a galvanic cell and at the anode in an electrolytic cell.
Q:
For a dead batteryA) E is negative and G is positive for the cell reaction.B) E is negative and G is negative for the cell reaction.C) E is zero and G is positive for the cell reaction.D) E is zero and G is zero for the cell reaction.
Q:
For an electrolytic cellA) E is negative and G is negative for the cell reaction.B) E is negative and G is positive for the cell reaction.C) E is positive and G is negative for the cell reaction.D) E is positive and G is positive for the cell reaction.
Q:
An electrolytic cell is
A) a battery.
B) a cell in which the cell reaction is spontaneous.
C) a cell in which an electric current drives a nonspontaneous reaction.
D) a cell in which reactants are continuously supplied to the cell.
Q:
A steel pipe can be protected from corrosion by attaching the pipe to a piece of magnesium because
A) magnesium forms a tight oxide coating.
B) magnesium is more easily oxidized than iron.
C) magnesium is inert.
D) magnesium and steel form a corrosion resistant alloy.
Q:
Aluminum requires relatively little protection from corrosion because
A) aluminum has little tendency to react with oxygen.
B) the reduction potential for Al3+/Al is very low.
C) the oxidation of aluminum produces a hard, relatively impenetrable film of Al2O3.
D) aluminum is protected by cathodic protection.
Q:
What is least easily oxidized?
A) Al
B) Fe
C) Mg
D) Zn
Q:
Galvanized steel is steel coated with a layer of
A) Fe2O3.
B) Mg.
C) Sn.
D) Zn.
Q:
Which of the following statements concerning the rusting of iron is false?
A) The oxidation site can occur at a different place on the metal surface than the reduction site.
B) The metal is reduced.
C) The rusting of iron requires both oxygen and water.
D) Salt increases the rate of corrosion by providing ions to carry the current.
Q:
Shown below are the reactions occurring in the proton-exchange membrane (PEM) fuel cell.I 2 H2(g) -> 4 H+(aq) + 4 e-II O2(g) + 4 H+(aq) + 4 e- -> 2 H2O(l)Overall 2 H2(g) + O2(g) -> 2 H2O(l)Which is the cathode reaction, and what is being oxidized in the overall reaction?A) I, H2B) I, O2C) II, H2D) II, O2
Q:
Shown below are the reactions occurring in the direct methanol fuel cell (DMFC).I 2 CH3OH(aq) + 2 H2O(l) -> 2 CO2(g) +12 H+(aq) +12 e-II 3 O2(g) + 12 H+(aq) + 12 e- -> 6 H2O(l)Overall 2 CH3OH(aq) + 3 O2(g) -> 2 CO2(g) + 4 H2O(l)Which is the anode reaction, and what is being oxidized in the overall reaction?A) I, CH3OHB) I, H2OC) II, O2D) II, H+
Q:
Which of the following statements concerning a lithium battery is false?
A) A lithium battery is rechargeable.
B) A lithium battery has a relatively high voltage, due in part to the high oxidation potential of lithium.
C) It takes a small mass of lithium to provide one mole of electrons in the cell reaction.
D) The cell reaction produces toxic mercury, so the batteries should be recycled.
Q:
Which of the following reactions is most suitable for a fuel cell?A) MnO2(s) + Li(s) -> LiMnO2(s)B) Pb(s) + PbO2(s) + 2 H+(aq) + HSO4-(aq) -> PbSO4(s) + 2 H2O(l)C) HgO(l) + Zn(s) -> ZnO(s) + Hg(l)D) 2 CO(g) + O2(g) -> 2 CO2(g)
Q:
Which statement below is not true?
A) The cell reactants in a fuel cell are continuously supplied from an external source.
B) A fuel cell is a galvanic cell.
C) Modern fuel cells can be easily regenerated using household current.
D) One of the reactants in a fuel cell is a traditional fuel.
Q:
Which battery does not use MnO2(s) as a cell reactant?
A) an alkaline dry cell.
B) a Leclanche' dry cell.
C) a lithium battery.
D) a "ni-cad" battery.
Q:
The cell reaction for a lead storage battery is:Pb(s) + PbO2(s) + 2 H+(aq) + 2 HSO4-(aq) -> 2 PbSO4(s) + 2 H2O(l)E = +1.92 VTo provide a potential of about 12 V, one couldA) adjust the pH to 12.B) adjust the pH to 1.C) connect six cells in series.D) greatly increase the surface area of the Pb(s) and PbO2(s).
Q:
For a particular battery based on one of the following reactions, E is expected to remain constant with time until the cell reactants are almost completely consumed. Which is the appropriate reaction?A) Zn(s) + 2 MnO2(s) + 2 NH4+(aq) -> 2 NH3(aq) + Mn2O3(s) + Zn2+(aq) + H2O(l)B) 2 NiO(OH)(s) + Cd(s) + 2 H2O(l) -> 2 Ni(OH)2(s) + Cd(OH)2(s)C) Pb(s) + PbO2(s) + 2 H+(aq) + 2 HSO4-(aq) -> 2 PbSO4(s) + 2 H2O(l)D) Zn(s) + Cu2+(aq) -> Zn2+(aq) + Cu(s)
Q:
A particular 12V battery is based on a reaction having a standard cell potential, E = +1.92 V. What happens when the battery "dies"?
A) E = 0 V and E = 0 V
B) E = 0 V and E = 12 V
C) E = +1.92 V and E = 0 V
D) E = +1.92 V and E = 12 V
Q:
For a particular cell based on the reaction:3 AgCl(s) + Al(s) -> 3 Ag(s) + Al3+(aq) + 3 Cl-(aq)E = +1.750 V and E = +1.884 V at 25C.What is the value of the equilibrium constant, K, at 25C for the reaction?A) 3.6 1029B) 6.7 1031C) 4.8 1088D) 3.0 1095