14.For the redox reaction 2Fe2+ + Cl2 2Fe3+ + 2Cl which of the following are the correct half-reactions?I.Cl2 + 2e 2Cl

II.Cl Cl + e

III.Cl2 2Cl + 2e

IV.Fe2+ Fe3+ + e

V.Fe2+ + e Fe3+

a)I and IVb)I and Vc)II and IVd)II and Ve)III and IVAns:a Algorithm:No Chapter/Section:18.1 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:half-reaction15.What is the oxidation state of Hg in Hg2Cl2?a)+2b)1c)2d)+1e)0Ans:d Algorithm:No Chapter/Section:18.1 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:chemicalreactions Keyword4:typesofchemicalreactions Keyword5:oxidation-reductionreaction Keyword6:assigningoxidationnumber

16.How many electrons are transferred in the following reaction? 2ClO3 + 12H+ + 10I 5I2 + Cl2 + 6H2Oa)12b)5c)2d)30e)10Ans:e Algorithm:No Chapter/Section:18.1 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:half-reaction Keyword5:balancingchemicalequation17.How many electrons are transferred in the following reaction? Cd + 2HCl CdCl2 + H2a)0b)1c)2d)4e)not enough information givenAns:c Algorithm:Yes Chapter/Section:18.1 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:half-reaction Keyword5:balancingoxidation-reductionreactionsConsider a galvanic cell based in the reaction Fe2+ + Cr2O72 Fe3+ + Cr3+ in acidic solution.21.What is the coefficient of Fe3+ in the balanced equation?a)6b)2c)3d)4e)none of theseAns:a Algorithm:No Chapter/Section:18.1 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:half-reaction Keyword5:balancingoxidation-reductionreactions Keyword6:half-reactionmethod22.Calculate the voltage of the standard cell carrying out this reaction.a)0b)0.21 Vc)0.21 Vd)0.56 Ve)0.56 VAns:d Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs23.Which energy conversion shown below takes place in a galvanic cell?a)electrical to chemicalb)chemical to electricalc)mechanical to chemicald)chemical to mechanicale)mechanical to electricalAns:b Algorithm:No Chapter/Section:18.2 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells24.Which of the following reactions is possible at the anode of a galvanic cell?a)Zn Zn2+ + 2eb)Zn2+ + 2e Znc)Zn2+ + Cu Zn + Cu2+d)Zn + Cu2+ Zn2+ + Cue)two of theseAns:a Algorithm:No Chapter/Section:18.2 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells25.Which of the following is true for the cell shown here? Zn(s)Zn2+(aq) Cr3+(aq) Cr(s)a)The electrons flow from the cathode to the anode.b)The electrons flow from the zinc to the chromium.c)The electrons flow from the chromium to the zinc.d)The chromium is oxidized.e)The zinc is reduced.Ans:b Algorithm:No Chapter/Section:18.2 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells26.The anode in a voltaic cell and in an electrolytic cell isa)positive in both cellsb)the site of oxidation and of reduction, respectivelyc)the site of reduction and of oxidation, respectivelyd)the site of oxidation in both cellse)the site of reduction in both cellsAns:d Algorithm:No Chapter/Section:18.2 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells difficulty:easy27.Which statement is always true of the cathode in an electrochemical cell?a)It is considered the negative electrode.b)It is considered the positive electrode.c)Reduction occurs here.d)Metal is plated out here.e)Negative ions flow toward the cathode.Ans:c Algorithm:No Chapter/Section:18.2 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells difficulty:moderate28.A strip of copper is placed in a 1 M solution of copper nitrate and a strip of silver is placed in a 1 M solution of silver nitrate. The two metal strips are connected to a voltmeter by wires and a salt bridge connects the solutions. The following standard reduction potentials apply:Ag+(aq) + e Ag(s) = +0.80 V

Cu2+(aq) + 2e Cu(s) = +0.34 V

Which of the following statements is false?a)Electrons flow in the external circuit from the copper electrode to the silver electrode.b)The silver electrode increases in mass as the cell operates.c)There is a net general movement of silver ions through the salt bridge to the copper half-cell.d)Negative ions pass through the salt bridge from the silver half-cell to the copper half-cell.e)Some positive copper ions pass through the salt bridge from the copper half-cell to the silver half-cell.Ans:c Algorithm:No Chapter/Section:18.3 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells29.You are told that metal X is a better reducing agent than metal Y. This must mean that:a)X+ is a better oxidizing agent than Y+.b)X+ is a better reducing agent than Y+.c)Y is a better oxidizing agent than X.d)Y+ is a better reducing agent than X+.e)Y+ is a better oxidizing agent than X+.Ans:e Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:strength of oxidizing and reducing agents30.Which of the following species cannot function as an oxidizing agent?a)S(s)b)NO3(aq)c)Cr2O72(aq)d)I(aq)e)MnO4(aq)Ans:d Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials31.Which of the following is the strongest oxidizing agent? MnO4 + 4H+ + 3e MnO2 + 2H2O = 1.68 V

I2 + 2e 2I = 0.54 V

Zn2+ + 2e Zn = 0.76 V

a)MnO4b)I2c)Zn2+d)Zne)MnO2Ans:a Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:strength of oxidizing and reducing agents32.Which metal, Al or Ni could reduce Zn2+ to Zn(s) if placed in a Zn2+(aq) solution?Zn2+ + 2e Zn = 0.76 V

Al3+ + 3e Al = 1.66 V

Ni2+ + 2e Ni = 0.23 V

a)Alb)Nic)Both Al and Ni would work.d)Neither Al nor Ni would work.e)Cannot be determined.Ans:a Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:tabulating standard electrode potentials

33.Which of the following is the best reducing agent? Cl2 + 2e 2Cl = 1.36 V

Mg2+ + 2e Mg = 2.37 V

2H+ + 2e H2 = 0.00 V

a)Cl2b)H2c)Mgd)Mg2+e)Cl-Ans:c Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:strength of oxidizing and reducing agents34.Consider the galvanic cell shown below (the contents of each half-cell are written beneath each compartment):

0.50 M Br2 0.20 M Cr3+ 0.10 M BrThe standard reduction potentials are as follows:Cr3+(aq) + 3e Cr(s) = 0.725 VBr2(aq) + 2e 2Br(aq) = +1.090 VWhat is for this cell?a)1.815 Vb)0.365 Vc)0.365 Vd)4.720 Ve)1.320 VAns:a Algorithm:Yes Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs

35.Consider the galvanic cell shown below (the contents of each half-cell are written beneath each compartment):

0.50 M Br2 0.20 M Cr3+ 0.10 M BrThe standard reduction potentials are as follows:Cr3+(aq) + 3e Cr(s) = -0.73 VBr2(aq) + 2e 2Br(aq) = +1.09 V

Which of the following statements about this cell is false?a)This is a galvanic cell.b)Electrons flow from the Pt electrode to the Cr electrode.c)Reduction occurs at the Pt electrode.d)The cell is not at standard conditions.e)To complete the circuit, cations migrate into the left half-cell and anions migrate into the right half-cell from the salt bridge.Ans:b Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells36.Refer to the galvanic cell below (the contents of each half-cell are written beneath each compartment):

0.10 M MnO4 0.40 M Cr3+0.20 M Mn2+ 0.30 M Cr2O720.010 M H+ 0.010 M H+The standard reduction potentials are as follows:MnO4 + 8H+ + 5e Mn2+ + 4H2O, = 1.507 VCr2O72 + 14H+ + 6e 2Cr3+ + 7H2O, = 1.330 V

What is the value of cell?a)0.177b)2.837c)0.177d)0.677e)6.205Ans:c Algorithm:Yes Chapter/Section:18.5 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:dependenceofemfonconcentration Keyword6:Nernstequation

Use the following to answer questions 37-44:

Refer to the galvanic cell below (the contents of each half-cell are written beneath each compartment):

0.10 M MnO4 0.40 M Cr3+0.20 M Mn2+ 0.30 M Cr2O720.010 M H+ 0.010 M H+The standard reduction potentials are as follows:MnO4 + 8H+ + 5e Mn2+ + 4H2O, = 1.51 VCr2O72 + 14H+ + 6e 2Cr3+ + 7H2O, = 1.33 V37.When current is allowed to flow, which species is oxidized?a)Cr2O72b)Cr3+c)MnO4d)Mn2+e)H+Ans:b Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells38.When current is allowed to flow, which species is reduced?a)Cr2O72b)Cr3+c)MnO4d)Mn2+e)H+Ans:c Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells

39.What is the oxidation state of Cr in Cr2O72?a)+7b)+6c)+12d)1e)2Ans:b Algorithm:No Chapter/Section:18.1 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:chemicalreactions Keyword4:typesofchemicalreactions Keyword5:oxidation-reductionreaction Keyword6:assigningoxidationnumber40.What is the value of Q, the reaction quotient, for this cell reaction?a)6.7 1040b)1.5 1041c)1.5 104d)6.7 103e)none of theseAns:b Algorithm:No Chapter/Section:18.5 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:dependenceofemfonconcentration41.In which direction do electrons flow in the external circuit?a)left to rightb)right to leftc)no current flows; the cell is at equilibriumd)cannot be determined.e)none of theseAns:b Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:constructionofvoltaiccells45.A cell is set up with copper and lead electrodes in contact with CuSO4(aq) and Pb(NO3)2(aq), respectively, at 25C. The standard reduction potentials are: Pb2+ + 2e Pb = 0.13 V Cu2+ + 2e Cu = +0.34 VIf the Pb2+ and Cu2+ are each 1.0 M, the potential of the cell, in volts, is:a)0.47 Vb)0.92 Vc)0.22 Vd)0.58 Ve)none of theseAns:a Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs46.Consider an electrochemical cell with a zinc electrode immersed in 1.0 M Zn2+ and a silver electrode immersed in 1.0 M Ag+.Zn2+ + 2e Zn = 0.755 VAg+ + e Ag = 0.800 VCalculate for this cell.a)0.045 Vb)0.045 Vc)1.555 Vd)1.555 Ve)none of theseAns:c Algorithm:Yes Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs

47.The galvanic cell described by Zn(s)Zn2+(aq)Cu2+(aq)Cu(s) has a standard cell potential of 1.101 volts. Given that Zn(s) Zn2+(aq) + 2e has an oxidation potential of 0.762 volts, determine the reduction potential for .a)1.863 Vb)1.863 Vc)0.339 Vd)0.339 Ve)none of theseAns:d Algorithm:Yes Chapter/Section:18.3 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials

48.The following question refers to a galvanic cell that utilizes the following reaction (unbalanced):(AuCl4)(aq) + Cu(s) Au(s) + Cl(aq) + Cu2+(aq)Given the following information, determine the standard cell potential:SpeciesStandard Reduction Potential (V)

Au3+(aq)1.4980

Cu2+(aq)-0.3391

a)1.1589 Vb)1.8371 Vc)3.8158 Vd)0.8198 Ve)4.1549 VAns:a Algorithm:Yes Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs49.Choose the correct statement given the following information: Fe3+(aq) + e Fe2+(aq) = 0.77 V Fe(CN)63(aq) + e Fe(CN)64(aq) = 0.36 Va)Fe2+(aq) is more likely to be oxidized than Fe2+ complexed to CN.b)Fe3+(aq) is more likely to be reduced than Fe3+ complexed to CN.c)Both A and B are true.d)Complexation of Fe ions with CN has no effect on their tendencies to become oxidized or reduced.e)None of these is true.Ans:b Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:strength of oxidizing and reducing agents50.The following question refers to the following system:3Ag(s) + NO3(aq) + 4H+(aq) 3Ag+(aq) + NO(g) + 2H2O(l)Anode reaction:Ag Ag+(aq) + e = 0.7990 VCathode reaction:NO3(aq) + 4H+(aq) + 3e NO(g) + 2H2O(l) = 0.9639 VDetermine the standard cell potential.a)1.7629 Vb)0.1649 Vc)2.0927 Vd)3.5258 Ve)0.5876 VAns:b Algorithm:Yes Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs

51.Which of the following would be the best oxidizing agent?a)Cl2b)Fec)Nad)Na+e)FAns:a Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:strength of oxidizing and reducing agents52.Copper will spontaneously reduce which of the following?a)Fe2+ and Ag+b)Fe2+c)Ag+d)Al3+e)Fe2+ and Al3+Ans:c Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:tabulating standard electrode potentials53.Determine the standard potential, , of a cell that employs the reaction:Fe + Cu2+ Cu + Fe2+.Reaction (volts)

Fe2++ 2e Fe0.440

Cu2++ 2e Cu+0.340

a)0.100b)0.780c)0.100d)0.780e)0.200Ans:d Algorithm:Yes Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs54.Of Sn2+, Ag+, and/or Zn2+, which could be reduced by Cu?a)Sn2+b)Ag+c)Zn2+d)Two of them could be reduced by Cu.e)All of them could be reduced by Cu.Ans:b Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:tabulating standard electrode potentials55.You wish to plate out zinc metal from a zinc nitrate solution. Which metal, Al or Ni, could you place in the solution to accomplish this?a)Alb)Nic)Both Al and Ni would work.d)Neither Al nor Ni would work.e)Cannot be determined.Ans:a Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:tabulating standard electrode potentials56.Which of the following is the best reducing agent?a)Cl2b)H2c)Mgd)Mg2+e)ClAns:c Algorithm:No Chapter/Section:18.3 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:strength of oxidizing and reducing agents65.Which of the following statements is true concerning the electrochemical cell depicted below?Ca | Ca2+(aq) || Mn2+(aq) | MnCa2+(aq) + 2e Ca(s); = 2.87 VMn2+(aq) + 2e Mn(s); = 1.19 Va)The cell reaction is spontaneous with a standard cell potential of 1.68 V.b)The cell reaction is spontaneous with a standard cell potential of 4.06 V.c)The cell reaction is nonspontaneous with a standard cell potential of 1.68 V.d)The cell reaction is nonspontaneous with a standard cell potential of 4.06 V.e)The cell is at equilibrium.Ans:a Algorithm:Yes Chapter/Section:18.3 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs66.Which of the following statements is true concerning the electrochemical cell depicted below?Sr | Sr2+(aq) || Rb+(aq) | RbSr2+(aq) + 2e Sr(s); = 2.90 VRb+(aq) + e Rb(s); = 2.98 Va)The cell reaction is spontaneous with a standard cell potential of 0.08 V.b)The cell reaction is nonspontaneous with a standard cell potential of 5.88 V.c)The cell reaction is nonspontaneous with a standard cell potential of 0.08 V.d)The cell reaction is spontaneous with a standard cell potential of 5.88 V.e)The cell is at equilibrium.Ans:c Algorithm:Yes Chapter/Section:18.3 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:standard cell emfs and standard electrode potentials Keyword6:calculatingcellemfs

67.The reduction potentials for Au3+ and Ni2+ are as follows:Au3+ + 3e Au, = +1.50 VNi2+ + 2e Ni, = 0.232 V

Calculate G (at 25C) for the reaction:2Au3+ + 2Ni 3Ni2+ + 2Aua)1.00 103 kJb)7.34 102 kJc)7.34 102 kJd)1.67 102 kJe)1.00 103 kJAns:e Algorithm:Yes Chapter/Section:18.4 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells74.Determine G for a cell that utilizes the following reaction:

Cl2(g) + 2Br(aq) 2Cl(aq) + Br2(l)The standard reduction for the chlorine gas is 1.360 volts and the standard reduction for the bromine liquid is about 1.076 volts.a)470 kJb)27.4 kJc)235 kJd)54.8 kJe)24.3 kJAns:d Algorithm:Yes Chapter/Section:18.4 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells77.A common car battery consists of six identical cells, each of which carries out the reaction:

Pb + PbO2 + 2HSO4 + 2H+ 2PbSO4 + 2H2OThe value of for such a cell is 2.041 V. Calculate G at 25 C for the reaction.a)196.9 kJb)98.46 kJc)393.9 kJd)787.7 kJe)590.8 kJAns:c Algorithm:Yes Chapter/Section:18.4 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells78.What is G for the following electrochemical equation? (red(Na+/Na) = 2.710 V, red(Zn2+/Zn) = 0.762 V)2Na(s) + Zn2+(aq) 2Na+(aq) + Zn(s)a)376 kJ/molb)188 kJ/molc)376 kJ/mold)752 kJ/mole)752 kJ/molAns:c Algorithm:Yes Chapter/Section:18.4 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells107.Which of the following statements is true concerning the electrochemical cell described below at 25oC?Cu | Cu2+(0.935 M) || Cu2+(0.982 M) | CuCu2+(aq) + 2e Cu(s); = 0.34 Va)The cell reaction is spontaneous with a cell potential of 1.10 mV.b)The cell reaction is spontaneous with a cell potential of 0.630 mV.c)The cell reaction is nonspontaneous with a cell potential of 0.630 mV.d)The cell reaction is nonspontaneous with a cell potential of 1.10 mV.e)The cell reaction is spontaneous with a cell potential of 0.34 V.Ans:b Algorithm:Yes Chapter/Section:18.5 Difficulty:Difficult Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:dependenceofemfonconcentration Keyword6:Nernstequation108.What is the potential at 25C for the following cell?CrCr3+(0.015 M)Ag+(0.00010 M)AgCr3+ + 3e Cr = 0.73 VAg+ + e Ag = 0.80 Va)2.09 Vb)1.33 Vc)0.95 Vd)1.73 Ve)1.49 VAns:b Algorithm:Yes Chapter/Section:18.5 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:dependenceofemfonconcentration Keyword6:Nernstequation109.T F Concentration cells work because standard reduction potentials are dependent on concentration.Ans:False Algorithm:No Chapter/Section:18.5 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells Keyword5:dependenceofemfonconcentration110.Consider the hydrogenoxygen fuel cell where:H2(g) + O2(g) H2O(l) G = 237.18 kJ/mol H2Which of the following statements is true?a)At standard conditions, the maximum work the fuel cell could do on the surroundings is 237.18 kJ/mol.b)In the real world, the actual amount of useful work the cell can do is less than 237.18 kJ.c)More energy is dissipated as waste heat in the fuel cell than in the reversible pathway.d)A, B, and C are all true.e)A, B, and C are all false.Ans:d Algorithm:No Chapter/Section:18.6 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:voltaiccells115.How many faradays are involved in conversion of a mole of Cu2O to CuO?a)1b)2c)3d)4e)5Ans:a Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis116.How many moles of electrons are produced from a current of 17.6 A in 3.00 hours?

a)5.47 104 molb)1.97 molc)52.8 mold)3.35 mol

e)9.33 103 molAns:b Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis

117.A common car battery consists of six identical cells each of which carries out the reaction:Pb + PbO2 + 2HSO4 + 2H+ 2PbSO4 + 2H2OSuppose that in starting a car on a cold morning a current of 125 amperes is drawn for 22.9 seconds from a cell of the type described above. How many grams of Pb would be consumed? (The atomic weight of Pb is 207.19.)a)6.15 gb)3.07 gc)5.86 103 gd)1.97 104 ge)1.48 102 gAns:b Algorithm:Yes Chapter/Section:18.8 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis

Use the following to answer questions 118-119:

An antique automobile bumper is to be chrome plated. The bumper, which is dipped into an acidic Cr2O72 solution, serves as a cathode of an electrolytic cell. The atomic mass of Cr is 51.996; 1 faraday = 96,485 coulombs.118.If oxidation of H2O occurs at the anode, how many moles of oxygen gas will evolve for every 145 grams of Cr(s) deposited?a)4.18b)0.697c)16.7d)11.2e)3.72Ans:a Algorithm:Yes Chapter/Section:18.8 Difficulty:Difficult Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis119.If the current is 10.0 amperes, how long will it take to deposit 137 grams of Cr(s) onto the bumper?a)7.06 hb)1.77 daysc)70.6 mind)2.63 mine)2 mo, 25 days, 14 h, and 6 sAns:b Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis

120.Copper is electroplated from CuSO4 solution. A constant current of 3.70 amp is applied by an external power supply. How long will it take to deposit 1.00 102 g of Cu? The atomic mass of copper is 63.546.a)22.8 hb)11.4 minc)1.75 daysd)11.10 se)3.26 hAns:a Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis121.What quantity of charge is required to reduce 21.4 g of CrCl3 to chromium metal? (1 faraday = 96,485 coulombs)a)1.30 104 Cb)3.91 104 Cc)6.19 102 Cd)2.06 102 Ce)none of theseAns:b Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis122.Electrolysis of a molten salt with the formula MCl, using a current of 3.86 amp for 16.2 min, deposits 1.52 g of metal. Identify the metal. (1 faraday = 96,485 coulombs)a)Lib)Nac)Kd)Rbe)CaAns:c Algorithm:No Chapter/Section:18.8 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:electrolysisofmoltensalts123.If a constant current of 4.3 amperes is passed through a cell containing Cr3+ for 1.0 hour, how many grams of Cr will plate out onto the cathode? (The atomic mass of Cr is 51.996.)a)8.3 gb)7.7 104 gc)2.8 gd)25 ge)5.3 102 gAns:c Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis124.If an electrolysis plant operates its electrolytic cells at a total current of 1.1 106 amp, how long will it take to produce one metric ton (one million grams) of Mg(s) from seawater containing Mg2+? (1 faraday = 96,485 coulombs)a)2.0 hb)2.0 daysc)60 mind)1.0 he)0.50 yearAns:a Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis125.Nickel is electroplated from a NiSO4 solution. A constant current of 2.03 amp is applied by an external power supply. How long will it take to deposit 100. g of Ni? The atomic mass of Ni is 58.69.a)45.0 hb)22.5 hc)49.3 mind)150.0 se)2.95 sAns:a Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis126.A solution of MnO42 is electrolytically reduced to Mn3+. A current of 7.32 amp is passed through the solution for 15.0 minutes. What is the number of moles of Mn3+ produced in this process? (1 faraday = 96,485 coulombs)a)0.0683b)0.205c)3.79 104d)0.0228e)1.52 103Ans:d Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis127.How many seconds would it take to deposit 17.3 g of Ag (atomic mass = 107.87) from a solution of AgNO3 using a current of 10.00 amp?a)3.09 103 sb)7.74 102 sc)4.64 103 sd)1.55 103 se)5.16 102 sAns:d Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis128.Gold (atomic mass = 197.0) is plated from a solution of chloroauric acid, HAuCl4; it deposits on the cathode. Calculate the time it takes to deposit 0.65 gram of gold, passing a current of 0.10 amperes. (1 faraday = 96,485 coulombs)a)27 hoursb)2.7 hoursc)53 minutesd)18 minutese)none of theseAns:b Algorithm:Yes Chapter/Section:18.8 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis129.An unknown metal (M) is electrolyzed. It took 74.1 s for a current of 2.00 amp to plate 0.107 g of the metal from a solution containing M(NO3)3. Identify the metal.a)Lab)Bic)Gad)Cue)RhAns:b Algorithm:No Chapter/Section:18.8 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis130.Gold is produced electrochemically from an aqueous solution of Au(CN)2 containing an excess of CN. Gold metal and oxygen gas are produced at the electrodes. How many moles of O2 will be produced during the production of 1.00 mole of gold?a)0.25b)0.50c)1.00d)3.56e)4.00Ans:a Algorithm:No Chapter/Section:18.8 Difficulty:Difficult Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:aqueouselectrolysis131.What mass of Ni(s) may be deposited from an aqueous NiCl2 solution if a current of 2.50 A is applied to the solution for 365 s? (red(Ni2+/Ni) = 0.257 V, F = 96485 C/mol)a)0.555 gb)1.11 gc)0.0713 gd)0.278 ge)1.08 gAns:d Algorithm:Yes Chapter/Section:18.8 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis132.What mass of chromium could be deposited by electrolysis of an aqueous solution of Cr2(SO4)3 for 175 minutes using a constant current of 13.0 amperes?a)0.187 gb)220.7 gc)0.409 gd)36.8 ge)24.5 gAns:e Algorithm:Yes Chapter/Section:18.8 Difficulty:Moderate Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:stoichiometryofelectrolysis133.Which of the following are incorrectly paired?a)Alumina pure aluminum oxideb)Downs cell electrolyzes molten sodium chloridec)Mercury cell used in preventing contamination of NaOH by NaCld)Hall-Heroult process uses cryolite in production of aluminume)All of these are correct.Ans:e Algorithm:No Chapter/Section:18.9 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:commercialelectrolyticprocesses134.Which of the following used to be more precious than gold or silver, due to difficulties refining it?a)copperb)aluminumc)tind)zince)ironAns:b Algorithm:No Chapter/Section:18.9 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:commercialelectrolyticprocesses135.What are the products of the chlor-alkali process?a)sodium and sodium chlorideb)sodium chloride and chlorinec)sodium and chlorined)sodium hydroxide and chlorinee)aluminum and cryoliteAns:d Algorithm:No Chapter/Section:18.9 Difficulty:Easy Keyword1:Chemistry Keyword2:generalchemistry Keyword3:electrochemistry Keyword4:electrolyticcells Keyword5:commercialelectrolyticprocesses