<p> Honors Chemistry</p><p>Mr. Urig</p><p>Ch 20-21 HW Packet: Oxidation and Reduction</p><p>What is a oxidation-reductions reaction?</p><p>How are oxidation numbers calculated?</p><p>I. Fill in the Blank</p><p>1. The oxidation number of an atom of an uncombined, neutral element is ______.</p><p>2. The oxidation number of a monatomic ion is ______.</p><p>3. Elements in Group 1A of the periodic table have an oxidation number of ______.</p><p>4. Elements in group 2A of the periodic table have an oxidation number of ______.</p><p>5. In most compounds, aluminum has an oxidation number of ______.</p><p>6. Fluorine in compounds has an oxidation number of ______-.</p><p>7. When combined with nonmetals, hydrogen’s oxidation number is ______.</p><p>8. Oxygen has an oxidation number of ______in most compounds and ions.</p><p>9. In a polyatomic ion, the sum of the oxidation numbers is ______.</p><p>10. In compounds, the sum of the oxidation numbers is ______.</p><p>II. Matching</p><p>11. _____ redox reaction</p><p>12. _____ reduction</p><p>13. _____ oxidizing agent</p><p>14. _____ oxidation number A. The substance that accepts electrons from another substance</p><p>B. A process in which electrons are transferred between reactants</p><p>C. The charge that an atom in a compound would have if the electrons in a bond belonged to the more electronegative atom.</p><p>D. The process by which a substance loses one or more electrons.</p><p>E. The substance that undergoes oxidation.</p><p>F. The process by which a substance gains one or more electrons.</p><p>III. Short Answer</p><p>15. Can a material be oxidized without another material being reduced? Why or why not?</p><p>16. What is the oxidation number of each element in the following compounds?</p><p>A. CaCO3</p><p>B. P4O6</p><p>C. N2O5</p><p>17. Which element is oxidized and which element is reduced in the following equations?</p><p>A. K2Cr2O7 + 14HI → 2KI + 2CrI3 + 3I2 + 7H2O B. Cu + 2AgNO3 → Cu(NO3)2 + 2Ag</p><p>C. Na2SO4 + 4C → Na2S + 4CO</p><p>18. Use the activity series to predict if the following reactions will occur. If a reaction does occur, write the complete, balanced equation for the reaction.</p><p>A. Zn + HgCl2 →</p><p>B. Ag + Pb(NO3)2 →</p><p>C. Cu + AgNO3 →</p><p>D. Pb + Cu(NO3)2 →</p><p>E. Fe + HgCl2 → F. Zn + CaClO4 →</p><p>G. Ag + Cu(NO3)2 →</p><p>IV. More matching</p><p>19. _____ redox of a silver halide</p><p>20. _____ corrosion</p><p>21. _____bleach</p><p>22. _____rust</p><p>23. _____explosives</p><p>A. The oxidation of a metal caused by a reaction between a metal and a substance in its environment</p><p>B. Typically contain both oxidizing and reducing agents</p><p>C. Photographic image formation</p><p>D. The oxidation product of iron</p><p>E. Protests a substance from oxidation</p><p>F. Oxidizing agent that removes color</p><p>V. Essay</p><p>24. List several ways to prevent corrosion and explain why they work VI. Balance the following redox reactions (all in acidic solution)</p><p>25. 2+ - 3+ 2+ Fe + MnO4 → Fe + Mn</p><p>26. 2- - 2- 2+ SO3 + MnO4 → SO4 + Mn</p><p>27. - 2+ Zn + NO3 → Zn + N2O 28. - - - MnO4 + I → MnO2 + IO</p><p>29. - - P + NO3 → H2PO4 + NO</p><p>30. - - NO3 + I2 → IO3 + NO2</p><p>31. - - - - I + ClO → IO3 + Cl 32. 2- - 2- SO3 + MnO4 → SO4 + MnO2</p><p>33. - 3+ - 5+ BrO3 + Sb → Br + Sb</p><p>34. - 2+ C2H4 + MnO4 → CO2 + Mn</p><p>35. 2- - 3+ CrO4 + Cl → Cr + HClO2 36. Cd + AgCl → Cd2+ + Ag + Cl-</p><p>37. - - 2+ MnO4 + Cl → Mn + Cl2</p><p>VII. True/False – Correct False answers</p><p>38. _____ Oxidation involves the gaining of electrons.</p><p>39. _____ The transfer of electrons is the basis for electricity.</p><p>40. _____ Most metals are poor conductors of electrical current.</p><p>41. _____ Voltaic cells use nonspontaneous oxidation-reduction reactions.</p><p>42. _____ The electrons in a voltaic cell move from lower energy state to a higher energy state. 43. _____ Electric current is made possible by the movement of positive and negative ion s.</p><p>44. _____ A battery is an example of an electrolytic cell.</p><p>45. _____ The direct transfer of electrons makes voltaic cells work.</p><p>46. _____ The negative electrode of a voltaic cell is the cathode.</p><p>47. _____ Electrons move from a higher energy state to a lower energy state.</p><p>48. _____ Cell voltage is another term for cell potential.</p><p>49. _____ The voltage of any voltaic cell is always positive.</p><p>50. _____ The reference electrode for determining potentials is the standard oxygen electrode.</p><p>51. _____ A positive reduction potential shows that a metal is easier to reduce than hydrogen.</p><p>52. _____ Rechargeable batteries use internal power source to reverse reactions.</p><p>53. _____ A common dry-cell uses porous paper as its salt bridge.</p><p>54. _____ An alkaline dry cell has a shorter shelf life that a common dry cell.</p><p>55. _____ In a lead storage battery, the electrolyte is sulfuric acid.</p><p>56. _____ In a nickel-cadmium battery, the anode is composed of cadmium.</p><p>57. _____ Most electrolytic cells use inert electrodes.</p><p>58. _____ In the electrolysis of water, oxygen forms at the anode.</p><p>59. _____ The electrolysis of molten sodium chloride forms chlorine gas.</p><p>60. _____ The electrolysis of water is a commercially important source of hydrogen.</p><p>61. _____ In electroplating, the plating metal is the cathode of the cell.</p><p>VIII. Essays</p><p>62. How does an electrolytic cell differ from a voltaic cell. 63. When a car will not start because the battery is “dead” what does that mean chemically?</p><p>64. Why is a salt bridge necessary in a voltaic cell?</p><p>IX. Calculate Cell Potentials</p><p>65. What is the cell potential for a cell with a nickel electrode in contact with a Ni2+ solution and a silver electrode in contact with Ag+ ions? 66. What is the cell potential for a cell with a aluminum electrode in contact with a Al3+ solutions and an iron electrode in contact with Fe3+ ions?</p><p>67. What is the cell potential for a cell with a sodium electrode in contact with Na+ ions and a copper electrode in contact with Cu2+ ions?</p><p>68. What is the cell potential for a cell with a calcium electrode in contact with Ca2+ ions and a tin electrode in contact with Sn2+ ions?</p><p>69. Using the following reactions:</p><p>Pb2+ (aq) + 2e- → Pb(s)</p><p>Au3+ (aq) + 3e- → Au(s)</p><p>A. Which is the anode? Cathode?</p><p>B. What is the cell potential? 70. What is the cell potential for a cell with a nickel electrode in contact with Ni2+ and a copper electrode in contact with Cu2+ ions?</p><p>71. Using the following reactions:</p><p>Mn2+ (aq) + 2e- → Mn(s)</p><p>Cu2+ (aq) + 2e- → Cu(s)</p><p>A. Which is the anode? Cathode?</p><p>B. What is the cell potential?</p><p>72. What is the voltage produced by a voltaic cell consisting of a lead electrode in contact with a solution of Pb2+ ions and an iron electrode in contact with a solution of Fe2+ ions? Which is the anode and which is the cathode? 73. What is the voltage produced by a voltaic cell consisting of a zinc electrode in contact with a solution of Zn2+ ions and a silver electrode in contact with a solution of Ag+ ions?</p><p>74. Calculate the standard potential produced by a voltaic cell consisting of a gold electrode in contact with a solution of Au3+ ions and a silver electrode in contact with a solution of Ag+ ions. Which is the anode and which is the cathode?</p>