Chemistry, The Central Science, 11th edition Theodore L. Brown, H. Eugene LeMay, Jr., Bruce E. Bursten, and Catherine J. Murphy Chapter 20 Electrochemistry Dana & Michelle Chatellier University of Delaware © Copyright 2009, Pearson Education The oxidation state of nitrogen in the ammonium ion (NH4+) is: a. b. c. d. +1 0 –1 –3 The oxidation state of nitrogen in the ammonium ion (NH4+) is: a. b. c. d. +1 0 –1 –3 The oxidation state of manganese in the permanganate ion (MnO4-1) is: a. b. c. d. –1 +2 +4 +7 The oxidation state of manganese in the permanganate ion (MnO4-1) is: a. b. c. d. –1 +2 +4 +7 Zn + Cu2+ Zn2+ + Cu In the reaction above, the reducing agent is: a. b. c. d. Zn Cu2+ Zn2+ Cu Zn + Cu2+ Zn2+ + Cu In the reaction above, the reducing agent is: a. b. c. d. Zn Cu2+ Zn2+ Cu A large positive value of the standard reduction potential indicates __________ reaction. a. b. c. d. an equilibrium a spontaneous a nonspontaneous a very fast A large positive value of the standard reduction potential indicates __________ reaction. a. b. c. d. an equilibrium a spontaneous a nonspontaneous a very fast G = Gibbs free energy. F = Faraday’s Constant. E = the cell potential. n = the number of moles of electrons. The free energy change, ∆G, equals: a. b. c. d. F + nE F – nE –nFE nF – E G = Gibbs free energy. F = Faraday’s Constant. E = the cell potential. n = the number of moles of electrons. The free energy change, ∆G, equals: a. b. c. d. F + nE F – nE –nFE nF – E In a concentration cell, the halfreactions occurring at the anode and the cathode are: a. b. c. d. the same. in equilibrium. acid-base reactions. different in color. In a concentration cell, the halfreactions occurring at the anode and the cathode are: a. b. c. d. the same. in equilibrium. acid-base reactions. different in color. A cell that uses an external source of energy to produce an oxidation-reduction reaction is called __________ cell. a. b. c. d. a galvanic a voltaic an electrolytic a prison A cell that uses an external source of energy to produce an oxidation-reduction reaction is called __________ cell. a. b. c. d. a galvanic a voltaic an electrolytic a prison Q = charge in coulombs. I = current in amperes. t = time in seconds. Which is correct? a. b. c. d. Q=I+t Q=I–t Q=I/t Q = It Q = charge in coulombs. I = current in amperes. t = time in seconds. Which is correct? a. b. c. d. Q=I+t Q=I–t Q=I/t Q = It Reduction occurs at the: a. anode in both galvanic and electrolytic cells. b. cathode in both galvanic and electrolytic cells. c. anode in galvanic cells and cathode in electrolytic cells. d. cathode in galvanic cells and anode in electrolytic cells. Reduction occurs at the: a. anode in both galvanic and electrolytic cells. b. cathode in both galvanic and electrolytic cells. c. anode in galvanic cells and cathode in electrolytic cells. d. cathode in galvanic cells and anode in electrolytic cells. Oxidation occurs at the: a. anode in both galvanic and electrolytic cells. b. cathode in both galvanic and electrolytic cells. c. anode in galvanic cells and cathode in electrolytic cells. d. cathode in galvanic cells and anode in electrolytic cells. Oxidation occurs at the: a. anode in both galvanic and electrolytic cells. b. cathode in both galvanic and electrolytic cells. c. anode in galvanic cells and cathode in electrolytic cells. d. cathode in galvanic cells and anode in electrolytic cells.