Raymond Chang 10th edition Chapter 19 Chemistry Raymond Chang 10th edition Chapter 19 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Question 1 Which of the following is not a balanced half reaction? A) Ag+ → Ag + 1e- B) Cu+ + 1e- → Cu C) Cu2+ + 2e- → Cu D) Cu → Cu+ + 1e-

Question 2 Which of the following is false? A) In a galvanic electrochemical cell the cathode is the place where reduction occurs. B) In an electrolytic electrochemical cell the cathode is the place where reduction occurs. C) All types of electrochemical cells have both a cathode and an anode. D) The cell potential is equal to the standard cell potential when the cell is at equilibrium.

Question 3 The purpose of a salt bridge in an electrochemical cell is A) to give electrons a path to flow between the cathode and anode. B) to allow the reactants to mix so that reaction can occur. C) to maintain a balance of charge between the two half cells and thus allow a complete circuit. D) all of the above.

Question 4 In an electrolytic electrochemical cell, electrons flow from the cathode to the anode. A) True B) False

Question 5 The reduction of one mole of copper(II) ions to copper metal requires the transfer of one Faraday (about 96,500 Coulombs) of charge. A) True B) False

Question 6 The oxidation of one mole of silver metal to silver(I) ions requires the transfer of one Faraday (about 96,500 Coulombs) of charge. A) True B) False

Question 7 The electrochemical potential of a cell depends on which of the following? A) The standard reduction potential for the half-reaction that occurs at the anode. B) The standard reduction potential for the half-reaction that occurs at the cathode. C) The concentrations of species in the cell. D) All of the above.

Question 8 A current of 10. A is used for 75 s Question 8 A current of 10. A is used for 75 s. How many grams of copper metal could be plated out of a copper(II) solution? A) 0.0099 g B) 0.25 C) 0.49 D) 0.99

Question 9 Increasing the concentration of products in an electrochemical reaction will decrease the value of the standard electrochemical potential for the reaction. A) True B) False

Question 10 Increasing the concentration of products in an electrochemical reaction will decrease the value of the electrochemical potential for the reaction. A) True B) False

Question 11 What is the oxidation number of manganese in MnO42-? C) +7 D) +4

Ba(s) + F2(g) →BaF2 Question 12 Consider the following reaction: Which of the following statements is false? A) The barium atom is gaining electrons; therefore, it is reduced. B) The fluorine atom is gaining electrons; therefore, it is reduced. C) The barium atom is losing electrons; therefore, it is oxidized. D) none of the above E) all of the above

Question 13 In which of the following species is the oxidation number of manganese highest? A) MnO2 B) Mn2(SO4)3 C) K2MnO4 D) MnO3 E) KMnO4

Question 14 In a galvanic cell A) oxidation takes place at the anode. B) oxidation takes place at the cathode. C) none of the above.

Question 15 Choose the false statement: A) bromine will oxidize the iodide ion B) chlorine will oxidize the fluoride, bromide and iodide ions C) iodine will not oxidize any halides D) fluorine will oxidize all halides E) none of the above

Question 16 Which of the following metals is most easily oxidized? A) Mn B) Ag C) Al D) Cu E) Fe

Question 17 Electrolysis of an aqueous sodium chloride solution will produce: A) H2 and O2 B) H2 and Cl2 C) Na and O2 D) Na and Cl2 E) cannot take place

Question 18 It is possible to obtain zinc metal by placing a strip of copper in an aqueous solution of ZnSO4. A) True B) False

Question 19 Which kind of battery is rechargeable? A) mercury B) lead C) dry cell D) fuel cell E) none are rechargeable

Question 20 Calculate the mass of copper that can be deposited by the electrolysis of a solution of cupric sulfate if a 1.50 A current is passed through the solution for exactly 5 minutes. A) 0.148 g B) 0.296 g C) 0.372 g D) 0.744 g E) none of the above

Answer Key – Chapter 19 A D C B B A E C