Science

Q: Consider the following cell reaction:Zn(s) + 2H+(aq) →Zn2+(aq) + H2(g); Eºcell= 0.76VUnder standard-state conditions, what is Efor the following half-reaction?Zn2+(aq) + 2e-→Zn(s)A) B) C) D) E)

Q: Consider the following cell reaction:2Ag+(aq) + H2(g)→2H+(aq) + 2Ag(s); Eºcell= 0.80VUnder standard-state conditions, what is E for the following half-reaction?Ag+(aq) + 2e- →Ag(s)A) 0.80 VB) -0.40 VC) 0.40 VD) -0.80 VE) 1.10 V

Q: Consider the following reduction potentials:Cd2+(aq) + 2e- Cd(s); Eº= -0.40 VPb2+(aq) + 2e- Pb(s); Eº= -0.13 VCu2+(aq) + 2e- Cu(s); Eº= 0.34 VBr2(l) + 2e- 2Br-(aq); Eº= 1.07 VUnder standard-state conditions, which of the following reactions is spontaneous?A) Cd2+(aq) + Pb(s)→Cd(s) + Pb2+(aq)B) Pb2+(aq) + Cu(s)→Pb(s) + Cu2+(aq)C) 2Br-(aq) + Pb2+(aq)→Br2(l) + Pb(s)D) 2Br-(aq) + Cu2+(aq)→Br2(l) + Cu(s)E) Cu2+(aq) + Cd(s)→Cu(s) + Cd2+(aq)

Q: For a certain oxidation"reduction reaction, Eºcell is positive. This means thatA) Gº is negative and K is greater than 1.B) Gº is positive and K is less than 1.C) Gº is positive and K is greater than 1.D) Gº is negative and K is less than 1.E) Gº is zero and K is greater than 1.

Q: Consider the following standard reduction potentials:2H+(aq) + 2e- H2(g); Eº= 0.00 VSn2+(aq) + 2e- Sn(s); Eº= -0.15 VCd2+(aq) + 2e- Cd(s); Eº= -0.40 VWhich pair of substances will react spontaneously under standard-state conditions?A) Cd with H+B) Cd with SnC) Sn2+ with Cd2+D) Sn with Cd2+E) Sn2+ with H+

Q: Consider the following standard reduction potentials:Mg2+(aq) + 2e- Mg(s); Eº= -2.38 VV2+(aq) + 2e- V(s); Eº= -1.18 VCu2+(aq) + e- Cu+(aq); Eº= 0.15 VWhich of the following reactions will proceed spontaneously from left to right under standard-state conditions?A) Mg(s) + 2Cu2+(aq)→Mg2+(aq) + 2Cu+(aq)B) V2+(aq) + 2Cu+(aq)→V(s) + 2Cu2+(aq)C) Mg2+(aq) + 2Cu+(aq)→2Cu2+(aq) + Mg(s)D) Mg2+(aq) + V(s)→V2+(aq) + Mg(s)E) 2Cu2+(aq) + 2Cu+(aq)→Mg2+(aq) + Mg(s)

Q: Which of the following is true for a reaction that is nonspontaneous as written?A) Gº> 0; Eºcell< 0B) Gº< 0; Eºcell> 0C) Gº< 0; Eºcell< 0D) Gº> 0; Eºcell> 0E) Gº> 0; Eºcell= 0

Q: Which of the following statements is true about a voltaic cell for which Eºcell=-1.00V?A) The cathode is at a higher energy than the anode.B) It has Gº< 0.C) The reaction is nonspontaneous.D) The system is at equilibrium.E) It has K= 1.

Q: Given:Hg2+(aq) + 2e- Hg(s); Eº= 0.85 VLi+(aq) + e- Li(s); Eº= -3.04 VBr2(l) + 2e- 2Br-(aq); Eº= 1.07 VAu+(aq) + e- Au(s); Eº= 1.69 VCl2(g) + 2e- 2Cl-(aq); Eº= 1.36 VWhich of the following species is the best reducing agent?A) HgB) Li+C) AuD) Cl-E) Br-

Q: Given:Li+(aq) + e- Li(s); Eº= -3.04 VMg2+(aq) + 2e- Mg(s); Eº= -2.38 VFe2+(aq) + 2e- Fe(s); Eº= -0.41 VAg+(aq) + e- Ag(s); Eº= 0.80 VBr2(l) + 2e- 2Br-(aq); Eº= 1.07 VWhich of the following species is the best oxidizing agent?A) Mg2+B) Br-C) Fe2+D) LiE) Ag+

Q: Given:Pb2+(aq) + 2e" Pb(s); Eº= "0.13 VZn2+(aq) + 2e" Zn(s); Eº= "0.76 VAl3+(aq) + 3e" Al(s); Eº= "1.66 VMg2+(aq) + 2e" Mg(s); Eº= "2.38 VV2+(aq) + 2e" V(s); Eº= "1.18 VCu2+(aq) + 2e" Cu(s); Eº= 0.34 VWhich of the following cations is capable of oxidizing Pb to Pb2+under standard-state conditions?A) Al3+B) V2+C) Cu2+D) Mg2+E) Zn2+

Q: Given:Zn2+(aq) + 2e- Zn(s); Eº= -0.76 V2H+(aq) + 2e- H2(g); Eº= 0.00 VI2(s) + 2e- 2I-(aq); Eº= 0.54 VBr2(l) + 2e- 2Br-(aq); Eº= 1.07 VNi2+(aq) + 2e- Ni(s); Eº= -0.23 VCu2+(aq) + 2e- Cu(s); Eº= 0.34 VWhich of the following species will oxidize Ni but not Cu?A) Zn2+B) Br-C) H+D) I2E) Zn

Q: Given:Zn2+(aq) + 2e- Zn(s); Eº= -0.76 VCr3+(aq) + 3e- Cr(s); Eº= -0.74 VFe2+(aq) + 2e- Fe(s); Eº= -0.41 VCd2+(aq) + 2e- Cd(s); Eº= -0.40 VSn2+(aq) + 2e- Sn(s); Eº= -0.15 VHg2+(aq) + 2e- Hg(s); Eº= 0.85 VAu+(aq) + e- Au(s); Eº= 1.69 VUnder standard-state conditions, which of the following metals will reduce Hg2+to Hg but will not reduce Cd2+to Cd?A) CrB) ZnC) FeD) SnE) Au

Q: Given:W3+(aq) + 3e- W(s); Eº= 0.10 VPb2+(aq) + 2e- Pb(s); Eº= -0.13 VNi2+(aq) + 2e- Ni(s); Eº= -0.23 VCd2+(aq) + 2e- Cd(s); Eº= -0.40 VZn2+(aq) + 2e- Zn(s); Eº= -0.76 VAl3+(aq) + 3e- Al(s); Eº= -1.66 VMg2+(aq) + 2e- Mg(s); Eº= -2.38 VUnder standard-state conditions, which of the following metals will reduce W3+to W but will not reduce Ni2+to Ni?A) CdB) PbC) AlD) ZnE) Mg

Q: Given:2H+(aq) + 2e- H2(g); Eº= 0.00 VLi+(aq) + e- Li(s); Eº= -3.04 VF2(g) + 2e- 2F-(aq); Eº= 2.87 VAl3+(aq) + 3e- Al(s); Eº= -1.66 VPb2+(aq) + 2e- Pb(s); Eº= -0.13 VUnder standard-state conditions, which is the strongest reducing agent?A) Pb2+B) Al3+C) F-D) LiE) H+

Q: Given:Pb2+(aq) + 2e- Pb(s); Eº= -0.13 V2H+(aq) + 2e- H2(g); Eº= 0.00 VNO3-(aq) + 4H+(aq) + 3e- NO(g) + 2H2O(l); Eº= 0.96 VO2(g) + 4H+(aq) + 4e- 2H2O(l); Eº= 1.23 VPbO2(s) + SO42-(aq) + 4H+(aq) + 2e- PbSO4(s) + 2H2O(l); Eº=1.69VUnder standard-state conditions, which of the following is the best oxidizing agent?A) H+B) Pb2+C) PbO2D) O2E) NO3-

Q: Given:Zn2+(aq) + 2e" Zn(s); Eº= -0.76 VCo2+(aq) + 2e" Co(s); Eº= -0.28 VSn2+(aq) + 2e- Sn(s); Eº= -0.15 VPb2+(aq) + 2e- Pb(s); Eº= -0.13 VFe3+(aq) + e- Fe2+(aq); Eº= 0.77 VUnder standard-state conditions, which of the following pairs of elements or ions is capable of reducing Sn2+(aq) to Sn(s)?A) Zn(s) or Co(s)B) Pb(s) or Fe2+(aq)C) Co(s) or Pb(s)D) Fe2+(aq) or Zn(s)E) Zn2+(aq) or Co2+(aq)

Q: Given:Pb2+(aq) + 2e-Pb(s); Eº= -0.13 VMg2+(aq) + 2e- Mg(s); Eº= -2.38 VAg+(aq) + e- Ag(s); Eº= 0.80 V2H+(aq) + 2e- H2(g); Eº= 0.00 VUnder standard-state conditions, which of the following species is the best reducing agent?A) H2B) Mg2+C) Ag+D) PbE) Ag

Q: Given:Ni2+(aq) + 2e- Ni(s); Eº= -0.23 V2H+(aq) + 2e- H2(g); Eº= 0.00 VAg+(aq) + e- Ag(s); Eº= 0.80 VNO3-(aq) + 4H+(aq) + 3e- NO(g) + 2H2O(l); Eº= 0.96 VWhich of the following statements is true?A) Ni2+reacts spontaneously with 1 M H+(aq) to form H2.B) Ni2+reacts spontaneously with H2(g).C) Ag(s) reacts spontaneously with Ni2+.D) Ag(s) reacts spontaneously with 1 M NO3-in 1 MH+(aq).E) Ag(s) reacts spontaneously with 1 M H+(aq).

Q: Given:Ni2+(aq) + 2e- Ni(s); Eº= -0.23 VCu2+(aq) + 2e- Cu(s); Eº= 0.34 VCr2O72-(aq) + 14H+(aq) + 6e- 2Cr3+(aq) + 7H2O(l); Eº=1.33VWhich of the following species is the strongest oxidizing agent?A) NiB) Cr3+C) Cr2O72-D) Ni2+E) Cu

Q: Given:Mn2+(aq) + 2e- Mn(s); Eº= -1.18 VCu2+(aq) + 2e- Cu(s); Eº= 0.34 VCr2O72-(aq) + 14H+(aq) + 6e" 2Cr3+(aq) + 7H2O(l); Eº=1.33VWhich of the following species is the strongest reducing agent?A) MnB) CuC) Cr3+D) Mn2+E) Cr2O72-

Q: In a table of standard reduction potentials, the strongest reducing agents are the _______ species in the half-reactions with the _______ E values.A) reduced, most negativeB) oxidized, most positiveC) reduced, most positiveD) oxidized, most negativeE) none of these

Q: What is the balanced spontaneous reaction and standard cell potential of an electrochemical cell constructed from half cells with the following half reactions? Eº= -0.763V Eº= -0.130VA) Pb2+(aq) + Zn(s) → Pb(s) + Zn2+(aq); 0.633 VB) Pb(s) + Zn2+(aq) → Pb2+(aq) + Zn(s); -0.633 VC) Pb2+(aq) + Zn2+(aq) → Pb(s) + Zn(s); -0.893 VD) Pb2+(aq) + Zn(s) → Pb(s) + Zn2+(aq); 0.317 VE) Pb(s) + Zn2+(aq) → Pb2+(aq) + Zn(s); -0.317 V

Q: The cell potential of an electrochemical cell with the cell reactionAl(s) + Cr3+(aq) → Cr(s) + Al3+(aq)is 1.63 V. What is the maximum electrical work obtainable from this cell when 1.0 mol of Al is consumed?A) JB) JC) JD) JE) J

Q: A fuel cell designed to react grain alcohol with oxygen has the following net reaction:C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)The maximum work that 1 mol of alcohol can yield by this process is 1320kJ. What is the theoretical maximum voltage that this cell can achieve?A) 1.14 VB) 2.28 VC) 2.01 VD) 0.760 VE) 13.7 V

Q: Which of the following statments concerning electrochemical cell potentials is/are correct? 1) Electrons flow from a point of high electrical potential to a point of low electrical potential. 2) The potential difference between two points in a circuit is measured in coulombs. 3) The cell voltage is at its maximum when no current is flowing. A) 1 only B) 2 only C) 3 only D) 2 and 3 E) 1 and 3

Q: The Faraday constant is defined as A) The charge per mole of electrons. B) The charge on a single electron. C) The maximum work obtainable from an electrochemical cell. D) The electromotive force of the cell. E) The amount of charge moved between electrodes.

Q: What is the SI unit of potential difference? A) coulomb B) farad C) volt D) joule E) ampere

Q: What is the cell reaction for the following electrochemical cell?Pt | Fe2+(aq),Fe3+(aq) || Al3+(aq) | AlA) 3Fe2+(aq) + Al3+(s) → Al(s) + 3Fe3+(aq)B) 3Fe2+(aq) + 3Fe3+(aq) → Al(s) + Al3+(aq)C) Al(s) + 3Fe3+(aq) → Al3+(aq) + 3Fe2+(aq)D) Pt(s) + Fe2+(aq) + Al3+(aq) → Al(s) + Pt2+(aq) + Fe3+(aq)E) Al(s) + Al3+(aq) → 3Fe2+(aq) + 3Fe3+(aq)

Q: What is the cell reaction for the following electrochemical cell?Ni | Ni2+(aq) || Y3+(aq) | YA) 3Ni(s) + 2Y3+(aq) →2Y(s) + 3Ni2+(aq)B) 2Y(s) + 3Ni2+(aq) → 3Ni(s) + 2Y3+(aq)C) Ni(s) + Ni2+(aq) → Y(s) + Y3+(aq)D) Ni(s) + Y3+(aq) →Y(s) + Ni2+(aq)E) Y(s) + Ni2+(aq) →Ni(s) + Y3+(aq)

Q: For a galvanic cell using Fe | Fe2+(1.0 M) and Pb | Pb2+(1.0 M) half-cells, which of the following statements is correct?Fe2+(aq) + 2e- → Fe(s); Eº= -0.41 VPb2+(aq) + 2e- → Pb(s); Eº= -0.13 VA) The iron electrode is the cathode.B) When the cell has completely discharged, the concentration of Pb2+is zero.C) The mass of the iron electrode increases during discharge.D) The concentration of Pb2+decreases during discharge.E) Electrons leave the lead electrode to pass through the external circuit during discharge.

Q: Consider the following standard electrode potentials:Ag+(aq) + e- Ag(s); Eº= 0.80 VMn2+(aq) + 2e- Mn(s); Eº= -1.18 VWhich of the following statements is false concerning the electrochemical cell given below?Mn(s) | Mn2+(aq) || Ag+(aq) | Ag(s)A) The anode half-cell reaction is Mn(s)→ Mn2+(aq) + 2e-.B) The reducing agent is Ag(s).C) Under standard-state conditions, the cell potential is 1.98 V.D) The cell potential decreases with time.E) The oxidizing agent is Ag+(aq).

Q: What is the correct cell notation for a cell in which the hydrogen electrode is the anode and the cathode half-reaction is Co3+(aq) + e-→Co2+(aq).A) Pt(s) | H2(g) | H+(aq) || Co3+(aq), Co2+(aq) | Pt(s)B) Pt(s) | H2(g) | H+(aq) || Co3+(aq), Co2+(aq)C) Co2+(aq), Co3+(aq) || H+(aq) | H2(g) | Pt(s)D) Pt(s)| Co2+(aq), Co3+(aq) || H+(aq) | H2(g) | Pt(s)E) H2(g) | H+(aq) || Co2+(aq), Co3+(aq)

Q: What is the cell reaction for the following electrochemical cell?Cu | Cu2+(aq) || Ni2+(aq) | NiA) 2Cu(s) + Ni2+(aq) → Ni(s) + 2Cu2+(aq)B) Cu(s) + Cu2+(aq) → Ni(s) + Ni2+(aq)C) Cu(s) + Ni2+(aq) → Ni(s) + Cu2+(aq)D) 2Ni(s) + Cu2+(aq) → Cu(s) + 2Ni2+(aq)E) Ni(s) + Cu2+(aq) → Cu(s) + Ni2+(aq)

Q: What is the cell notation for the voltaic cell shown below? A) Zn2+(aq) | Zn(s) || Cu2+(aq) | Cu(s) B) Zn(s) | Zn2+(aq) || Cu(s) | Cu2+(aq) C) Zn(s) | Cu(s) || Zn2+(aq) | Cu2+(aq) D) Zn(s) | Zn2+(aq) || Cu2+(aq) | Cu(s) E) Zn2+(aq) | Zn(s) || Cu(s) | Cu2+(aq)

Q: What is the cell reaction for the following voltaic cell?Al(s) | Al3+(aq) || Br-(aq) | Br2(g) | Pt(s)A) 2Al(s) + 3Br2(g) 2Al3+(aq) + 6Br-(aq)B) Al(s) + Al3+(aq) Br-(aq) + Br2(g)C) 2Al3+(aq) + 6Br"(aq) 2Al(s) + 3Br2(g)D) Al(s) + 3Br2(g) Al3+(s) + 2Br-(aq)E) Al(s) + 2Br-(aq) Br2(g) + Al3+(aq)

Q: A zinc-copper voltaic cell is represented as follows:Zn(s) | Zn2+(1.0 M) || Cu2+(1.0 M) | Cu(s)Which of the following statements is false?A) The copper electrode is the anode.B) Reduction occurs at the copper electrode during discharge.C) The mass of the zinc electrode decreases during discharge.D) Electrons flow through the external circuit from the zinc electrode to the copper electrode.E) The concentration of Cu2+decreases during discharge.

Q: In the following electrochemical cell, what is the reduction half reaction?Mn(s) | Mn2+(aq) || Fe3+(aq), Fe2+(aq) | Pt(s)A) Fe3+(aq) + e-→Fe2+(aq)B) Fe2+(aq) + e-→Fe3+(aq)C) Fe2+(aq) + Pt(s) →Fe3+(aq) + e-D) Mn2+(aq) →Mn(s) + 2e-E) Mn(s) →Mn2+(aq) + 2e-

Q: In the following electrochemical cell, what is the role of the platinum?Cu(s) | Cu2+(aq) || Fe3+(aq), Fe2+(aq) | Pt(s)A) The platinum serves as the anode.B) The oxidation of Fe2+takes place at the surface of the platinum as the cell discharges.C) The reduction of Fe3+takes place at the surface of the platinum as the cell discharges.D) A and C.E) A and B.

Q: According to the following cell notation, which species is undergoing reduction? Sn | Sn2+(aq) || Mn2+(aq) | MnO2(s) | Pt(s) A) Mn2+(aq) B) Sn2+(aq) C) Sn(s) D) MnO2(s) E) Pt(s)

Q: What is the effect on the cell when a salt bridge in an electrochemical cell is completely clogged during cell discharge? 1) Each half-cell reaction stops. 2) The flow of ions to and from the salt bridge is disrupted. 3) The flow of current through the external circuit slows but does not stop. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2 and 3

Q: Which of the following cell reactions would require the use of an inert electrode?A) Fe(s) + 2Ag+(aq)→2Ag(s) + Fe2+(aq)B) 3Cu(s) + 2Au3+(aq)→3Cu2+ + 2Au(s)C) Fe(s) + 2Ag+(aq)→Fe2+(aq) + 2Ag(s)D) Fe(s) + 2MnO2(s) + 2NH4+(aq)→Fe2+(aq) + Mn2O3(s) + 2NH3(aq) + H2O(l)E) 3Zn2+(aq) + 2Al(s)→3Zn(s) + 2Al3+(aq)

Q: Which of the following statements is true concerning half-cell I as the voltaic cell shown below discharges?A) [Zn2+] increases with time, and [Cl-] increases with time.B) [Zn2+] decreases with time, and [Cl-] increases with time.C) [Zn2+] decreases with time, and [Cl-] decreases with time.D) [Zn2+] decreases with time, and [NO3-] increases with time.E) [Zn2+] increases with time, and [NO3-] increases with time.

Q: Which of the following statements is true concerning the voltaic cell shown below? A) The Cu cathode mass increases as the cell discharges. B) The Cu anode mass decreases as the cell discharges. C) The Cu anode mass increases as the cell discharges. D) The Cu cathode mass decreases as the cell discharges. E) The mass of the Cu electrode neither increases nor decreases as the cell discharges.

Q: Which reaction would be most likely to occur at the anode of a voltaic cell?A) PbSO4(s) + 2e-→Pb(s) + SO42-(aq)B) 2H2O(l) + 2e-→H2(g) + 2OH-(aq)C) 2H2O(l) → O2(g)+ 4H+(aq) + 4e-D) PbSO4(s) → Pb2+(aq) + SO42-(aq)E) 2H2O(l) → 2H2(g) + O2(g)

Q: A strip of iron is placed in a 1 M solution of iron(II) sulfate, and a strip of copper is placed in a 1 M solution of copper(II) chloride. The two solutions are connected with a salt bridge, and the two metals are connected by a wire. Reduction Half-Reaction Eº(V) Fe2+(aq) + 2e-Fe(s) -0.41 Cu2+(aq) + 2e- Cu(s) 0.34 Which of the following takes place?A) Sulfur deposits at the iron electrode.B) The Fe(II) concentration of the iron half-cell decreases.C) Copper atoms deposit at the cathode.D) Chlorine is produced at the copper electrode.E) Chlorine is produced at the iron electrode.

Q: The following reactions take place in a lead storage battery.Discharging: Pb(s) + PbO2(s) + 4H+(aq) + 2SO42-(aq) → 2PbSO4(s) + 2H2O(l)Charging: 2PbSO4(s) + 2H2O(l) → Pb(s) + PbO2(s) + 4H+(aq) + 2SO42-(aq)Which of the following statements is true?A) The concentration of H2SO4increases as the battery discharges.B) Pb is formed at the anode during discharge.C) Pb is formed at the cathode during charging.D) The mass of Pb decreases during charging.E) The mass of PbSO4remains constant during charging and discharging.

Q: Which statement concerning the cathode in an electrochemical cell is correct? A) Metal ions may be deposited as metal atoms on the cathode during cell discharge. B) When connected to an external circuit, the cathode develops a positive charge. C) Reduction occurs at the cathode during cell discharge. D) Positive ions flow towards the cathode during cell discharge. E) All of the above.

Q: The cell reaction for a certain alkaline dry cell isZn(s) + 2MnO2(s) + H2O(l) → Zn(OH)2(s) + Mn2O3(s)Which of the following statements concerning this cell is/are correct?1) MnO2(s) is oxidized to Mn2O3(s) during cell discharge.2) Water is consumed during the discharge of this cell.3) Zn(OH)2(s) forms at the anode during discharge of this cell.A) 1 onlyB) 2 onlyC) 3 onlyD) 2 and 3E) 1, 2 and 3

Q: The anode in a voltaic cell and in an electrolytic cell is A) the site of oxidation and of reduction, respectively. B) the site of reduction and of oxidation, respectively. C) positive in both cells. D) the site of reduction in both cells. E) the site of oxidation in both cells.

Q: A lead storage battery involves the following two half-reactions:PbSO4(s) + 2e-→Pb(s) + SO42-(aq); E= -0.36 VPbO2(s) + 4H+(aq) + SO42-(aq) + 2e-→PbSO4(s) + 2H2O(l); Eº=1.69VDuring the discharge reaction of the lead storage battery at 1.0 M concentrations, the cell potential and the reducing agent are, respectively,A) 2.05 V and PbO2.B) -2.05 V and PbO2.C) 1.33 V and Pb.D) -2.05 V and Pb.E) 2.05 V and Pb.

Q: The electrochemical reaction which powers a lead-acid storage battery is as follows:Pb(s) + PbO2(s) + 4H+(aq) + 2SO42-(aq) → 2PbSO4(s) + 2H2O(l)A single cell of this battery consists of a Pb electrode and a PbO2electrode, each submerged in sulfuric acid. What reaction occurs at the cathode during discharge?A) Pb(s) is reduced to PbSO4(s).B) PbO2(s) is reduced to PbSO4(s).C) PbO2(s) is oxidized to PbSO4(s).D) Pb(s) is oxidized to PbSO4(s).E) H+is oxidized to H2O(l) .

Q: Which of the following statements concerning a voltaic cell is/are correct? 1) Reduction occurs at the cathode. 2) A spontaneous reaction generates an electric current in a voltaic cell. 3) Without a salt bridge charge buildup will cause the cell reaction to stop. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2, and 3

Q: Which of the following statements is true for a voltaic (galvanic) cell? A) The electron flow is from the anode to the cathode. B) The electron flow is from the positive electrode to the negative electrode. C) The electron flow is from the negative cathode to the positive anode. D) The electron flow is through the salt bridge. E) The electron flow is from the oxidizing agent to the reducing agent through an external circuit.

Q: When the following oxidation-reduction reaction in basic solution is balanced, what is the lowest whole-number coefficient for OH-, and on which side of the balanced equation should it appear?Cr2O3(s) → Cr(OH)2(aq) + CrO42-(aq)A) 2, reactant sideB) 10, product sideC) 4, product sideD) 4, reactant sideE) 2, product side

Q: Balance the following oxidation-reduction occurring in acidic solution.MnO4-(aq) + Co2+(aq) → Mn2+(aq) + Co3+(aq)A) MnO4-(aq) + 8H+(aq) + 5Co2+(aq) → Mn2+(aq) + 4H2O(aq) + 5Co3+(aq)B) MnO4-(aq) + 8H+(aq) + Co2+(aq) → Mn2+(aq) + 4H2O(aq) + Co3+(aq)C) MnO4-(aq) + 4H2(g) + 5Co2+(aq) → Mn2+(aq) + 4H2O(aq) + 5Co3+(aq)D) MnO4-(aq) + 8H+(aq) + 2Co2+(aq) → Mn2+(aq) + 4H2O(aq) + 2Co3+(aq)E) MnO4-(aq) + Co2+(aq) → Mn2+(aq) + 2O2(g) + Co3+(aq)

Q: Balance the following half-reaction occurring in basic solution.MnO2(s) → Mn(OH)2(s)A) MnO2(s) + 2H2O(l) + 2e- → Mn(OH)2(s)+ 2OH-(aq)B) MnO2(s) + 2H2O(l) + 4e- → Mn(OH)2(s)+ (OH)2-(aq)C) MnO2(s) + H22+(aq) + 2e-→ Mn(OH)2(s)D) MnO2(s) + H2(g) → Mn(OH)2(s) + 2e-E) MnO2(s) + 2H2O(l) → Mn(OH)2(s)+ 2OH-(aq)

Q: When the following oxidation"reduction reaction in acidic solution is balanced, what is the lowest whole-number coefficient for H+, and on which side of the balanced equation should it appear?S2O82-(aq) + NO(g)→SO42-(aq) + NO3-(aq)A) 4, product sideB) 8, reactant sideC) 12, reactant sideD) 8, product sideE) 4, reactant side

Q: Balance the following half-reaction occurring in acidic solution.NO3-(aq) → NO(g)A) NO3-(aq) + 4H+(aq) + 3e- → NO(g) + 2H2O(l)B) NO3-(aq) + 2H2O(l) + 3e- → NO(g) + 4H+(aq)C) NO3-(aq) + 4H+(aq) → NO(g) + 2H2O(l) + 3e-D) NO3-(aq) + 3e- → NO(g) + 4H+(aq) + 2H2O(l)E) NO3-(aq) + 4H+(aq) → NO(g) + 2H2O(l)

Q: When the following oxidation-reduction reaction in acidic solution is balanced, what is the lowest whole-number coefficient for H+, and on which side of the balanced equation should it appear?MnO4-(aq) + Br-(aq) → Mn2+(aq) + Br2(l)A) 1, reactant sideB) 2, product sideC) 8, reactant sideD) 16, reactant sideE) 4, product side

Q: When the following oxidation-reduction reaction in acidic solution is balanced, what is the lowest whole-number coefficient for Rb+(aq)?Rb(s) + Cu2+(aq) → Rb+(aq) + Cu(s)A) 5B) 4C) 1D) 3E) 2

Q: When balancing oxidation-reduction reactions in acidic solution by the half-reaction method, the addition of the reactant H+is required to balance the productA) O2.B) OH-.C) O.D) H2O.E) none of these

Q: For which of the following processes would Sº be expected to be most positive?A) H2O(l) → H2O(s)B) NH3(g) + HCl(g) → NH4Cl(s)C) O2(g) + 2H2(g) → 2H2O(g)D) N2O4(g) → 2NO2(g)E) 2NH4NO3(s) → 2N2(g) + O2(g) + 4H2O(g)

Q: In which reaction is Sº expected to be negative?A) 2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(l)B) Ga(l) → Ga(s)C) H2O(l) + 2SO2(g) → H2SO4(l)D) CO2(g) → CO2(s)E) all of above

Q: The third law of thermodynamics states that A) the entropy of the universe is increasing. B) the entropy of the universe is constant. C) the entropy of the universe equals the sum of the entropy of system and that of the surroundings. D) the absolute entropy of a substance decreases with increasing temperature. E) the entropy is zero at 0 K for a perfect crystal.

Q: Which of the following is not a spontaneous process at 25ºC and 1atm pressure?A) salt dissolvingB) ice meltingC) water boilingD) iron rustingE) steam condensing

Q: Assuming H and S are constant with respect to temperature, under what conditions will a chemical reaction be spontaneous only at low temperatures?A) H is negative, and S is negative.B) H is positive, and S is positive.C) S = 0, and H is positive.D) H= 0, and S is negative.E) none of these

Q: The enthalpy of vaporization (Hºvap) of benzene is 30.7kJ/mol at its normal boiling point of 353.3 K. What is Sºvap at this temperature?A) 86.9 J/(mol·K)B) 0.087 J/(mol·K)C) 11.5 J/(mol·K)D) 0.0115 J/(mol·K)E) 383 J/(mol·K)

Q: At the normal boiling point of o-xylene, Hºvap= 36.2kJ/mol and Sºvap=86.7J/(mol K). What is the normal boiling point of o-xylene?A) 314 KB) 373 KC) 115 KD) 867 KE) 418 K

Q: The standard enthalpy of fusion of bromobenzene is 10.7kJ/mol at its melting point, 242.4K. What is the standard change in entropy for the melting of bromobenzene at its melting point?A) 0.0208 J/(mol·K)B) 44.1 J/(mol·K)C) -10.7 J/(mol·K)D) -348 J/(mol·K)E) 0.0441 J/(mol·K)

Q: The standard enthalpy of vaporization of chloroform is 29.2kJ/mol at its normal boiling point, 61.2ºC. What is the standard change in entropy for the vaporization of chloroform at its normal boiling point?A) 87.3 J/(mol·K)B) -29.2 J/(mol·K)C) 0.477 J/(mol·K)D) 0.0873 J/(mol·K)E) 477 J/(mol·K)

Q: The standard enthalpy of vaporization of Freon-10, CCl4, is 29.82 kJ/mol at its normal boiling point of 77ºC. What is the change of entropy for 1 mol of liquid Freon-10 when it vaporizes at its normal boiling point?A) 8.52 x10-2J/KB) 1.04 x104J/KC) 85.2 J/KD) 0.387 J/KE) 3.87 x102J/K

Q: The total entropy of a system and its surroundings always increases for a spontaneous process. This is a statement of A) the third law of thermodynamics. B) the law of constant composition. C) the second law of thermodynamics. D) the law of conservation of matter. E) the first law of thermodynamics.

Q: Which of the following compounds has the highest standard entropy per mole at 298 K? A) H2O(l) B) CaCO3(s) C) CO(g) D) SiO2(s) E) CH3OH(l)

Q: Which of the following has the lowest entropy per mole?A) liquid sodium at 100ºCB) gaseous sodium at 900ºC and 0.5 atmC) a solid solution of sodium in potassium at 30ºCD) gaseous sodium at 900ºC and 1 atmE) solid sodium at 30ºC

Q: Which of the following is true for the sublimation of a solid substance?A) S= 0 and H= 0.B) S< 0 and H< 0.C) S< 0 and H> 0.D) S> 0 and H> 0.E) S> 0 and H< 0.

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