{"id":3207,"date":"2019-04-22T18:53:46","date_gmt":"2019-04-22T18:53:46","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-introductorychemistry\/chapter\/end-of-chapter-material-30\/"},"modified":"2019-04-29T13:09:30","modified_gmt":"2019-04-29T13:09:30","slug":"end-of-chapter-material-30","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-introductorychemistry\/chapter\/end-of-chapter-material-30\/","title":{"raw":"End-of-Chapter Material","rendered":"End-of-Chapter Material"},"content":{"raw":"
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Additional Exercises<\/h3>\r\n \r\n
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  1. \r\n
    \r\n

    Oxidation was once defined as chemically adding oxygen to a substance. Use this reaction to argue that this definition is consistent with the modern definition of oxidation.<\/p>\r\n2 Mg +\u00a0O2<\/sub> \u2192\u00a02 MgO<\/span><\/span>\r\n\r\n<\/div><\/li>\r\n \t

  2. \r\n
    \r\n

    Reduction was once defined as chemically adding hydrogen to a substance. Use this reaction to argue that this definition is consistent with the modern definition of reduction.<\/p>\r\nC2<\/sub>H2<\/sub> +\u00a02 H2<\/sub> \u2192\u00a0C2<\/sub>H6<\/sub><\/span><\/span>\r\n\r\n<\/div><\/li>\r\n \t

  3. \r\n
    \r\n

    Assign oxidation numbers to the atoms in each substance.<\/p>\r\n\r\n<\/div><\/li>\r\n<\/ol>\r\na) \u00a0Kr (krypton)\r\n\r\nb) \u00a0krypton tetrafluoride (KrF4<\/sub>)\r\n\r\nc) \u00a0dioxygen difluoride (O2<\/sub>F2<\/sub>)\r\n\r\n \r\n

    \r\n

    4. \u00a0Assign oxidation numbers to the atoms in each substance.<\/p>\r\na) \u00a0lithium hydride (LiH)\r\n\r\nb) \u00a0potassium peroxide (K2<\/sub>O2<\/sub>)\r\n\r\nc) \u00a0potassium fluoride (KF)\r\n\r\n<\/div>\r\n \r\n

    \r\n

    5. \u00a0N atoms can have a wide range of oxidation numbers. Assign oxidation numbers for the N atom in each compound, all of which are known compounds.<\/p>\r\na) \u00a0N2<\/sub>O5<\/sub>\r\n\r\nb) \u00a0N2<\/sub>O4<\/sub>\r\n\r\nc) \u00a0NO2<\/sub>\r\n\r\nd) \u00a0NO\r\n\r\ne) \u00a0N2<\/sub>H4<\/sub>\r\n\r\nf) \u00a0NH3<\/sub>\r\n\r\n<\/div>\r\n \r\n

    \r\n

    6. \u00a0Cr atoms can have a wide range of oxidation numbers. Assign oxidation numbers for the Cr atom in each compound, all of which are known compounds.<\/p>\r\na) \u00a0Na2<\/sub>CrO4<\/sub>\r\n\r\nb) \u00a0Na2<\/sub>Cr2<\/sub>O7<\/sub>\r\n\r\nc) \u00a0CrF5<\/sub>\r\n\r\nd) \u00a0CrCl3<\/sub>\r\n\r\ne) \u00a0CrCl2<\/sub>\r\n\r\n<\/div>\r\n \r\n

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    7. \u00a0Balance this redox reaction by inspection.<\/p>\r\nS8<\/sub> +\u00a0O2<\/sub> \u2192\u00a0SO2<\/sub><\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    8. \u00a0Balance this redox reaction by inspection.<\/p>\r\nC18<\/sub>H38<\/sub> +\u00a0O2<\/sub> \u2192\u00a0CO2<\/sub> +\u00a0H2<\/sub>O<\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    9. \u00a0Balance this redox reaction by the half reaction method by assuming an acidic solution.<\/p>\r\nCr2<\/sub>O7<\/sub>2\u2212<\/sup> +\u00a0Fe \u2192\u00a0Cr3+<\/sup> +\u00a0Fe3+<\/sup><\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    10. \u00a0Balance the redox reaction in Exercise 9 by the half reaction method by assuming a basic solution.<\/p>\r\n\r\n<\/div>\r\n \r\n

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    11. \u00a0The uranyl ion (UO2<\/sub>2+<\/sup>) is a fairly stable ion of uranium that requires strong reducers to reduce the oxidation number of uranium further. Balance this redox reaction using the half reaction method by assuming an acidic solution.<\/p>\r\nUO2<\/sub>2+<\/sup> +\u00a0HN3<\/sub> \u2192\u00a0U +\u00a0N2<\/sub><\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    12. \u00a0Balance the redox reaction in Exercise 11 by the half reaction method by assuming a basic solution.<\/p>\r\n\r\n<\/div>\r\n \r\n

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    13. \u00a0Zinc metal can be dissolved by acid, which contains H+<\/sup> ions. Demonstrate that this is consistent with the fact that this reaction has a spontaneous voltage:<\/p>\r\nZn +\u00a02 H+<\/sup> \u2192\u00a0Zn2+<\/sup> +\u00a0H2<\/sub><\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    14. \u00a0Copper metal cannot be dissolved by acid, which contains H+<\/sup> ions. Demonstrate that this is consistent with the fact that this reaction has a nonspontaneous voltage:<\/p>\r\nCu +\u00a02 H+<\/sup> \u2192\u00a0Cu2+<\/sup> +\u00a0H2<\/sub><\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    15. \u00a0A disproportionation reaction occurs when a single reactant is both oxidized and reduced. Balance and determine the voltage of this disproportionation reaction. Use the data in Table 14.1 \"Standard Reduction Potentials of Half Reactions\"<\/a>.<\/p>\r\nCr2+<\/sup> \u2192\u00a0Cr +\u00a0Cr3+<\/sup><\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    16. \u00a0A disproportionation reaction occurs when a single reactant is both oxidized and reduced. Balance and determine the voltage of this disproportionation reaction. Use the data in Table 14.1 \"Standard Reduction Potentials of Half Reactions\"<\/a>.<\/p>\r\nFe2+<\/sup> \u2192\u00a0Fe +\u00a0Fe3+<\/sup><\/span><\/span>\r\n\r\n<\/div>\r\n \r\n

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    17. \u00a0What would be overall reaction for a fuel cell that uses CH4<\/sub> as the fuel?<\/p>\r\n\r\n<\/div>\r\n \r\n

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    18. \u00a0What would be overall reaction for a fuel cell that uses gasoline (general formula C8<\/sub>H18<\/sub>) as the fuel?<\/p>\r\n\r\n<\/div>\r\n \r\n

    \r\n

    19. \u00a0When NaCl undergoes electrolysis, sodium appears at the cathode. Is the definition of cathode the same for an electrolytic cell as it is for a voltaic cell?<\/p>\r\n\r\n<\/div>\r\n \r\n

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    20. \u00a0When NaCl undergoes electrolysis, chlorine appears at the anode. Is the definition of anode the same for an electrolytic cell as it is for a voltaic cell?<\/p>\r\n\r\n<\/div>\r\n \r\n

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    21. \u00a0An award is being plated with pure gold before it is presented to a recipient. If the area of the award is 55.0 cm2<\/sup> and will be plated with 3.00 \u00b5m of Au, what mass of Au will be plated on the award? The density of Au is 19.3 g\/cm3<\/sup>.<\/p>\r\n\r\n<\/div>\r\n \r\n

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    22. \u00a0The unit of electrical charge is called the coulomb (C). It takes 96,500 coulombs of charge to reduce 27.0 g of Al from Al3+<\/sup> to Al metal. At 1,040 cm3<\/sup>, how many coulombs of charge were needed to reduce the aluminum in the cap of the Washington monument, assuming the cap is pure Al? The density of Al is 2.70 g\/cm3<\/sup>.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n

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    \r\n

    Answers<\/h3>\r\n1.<\/strong>\r\n\r\nAs oxygen is added to magnesium, it is being oxidized. In modern terms, the Mg atoms are losing electrons and being oxidized, while the electrons are going to the O atoms.\r\n\r\n3.<\/strong>\r\n\r\na) \u00a0Kr: 0\r\n\r\nb) \u00a0Kr: +4; F: \u22121\r\n\r\nc) \u00a0O: +1; F: \u22121\r\n\r\n5.<\/strong>\r\n\r\na) \u00a0+5\r\n\r\nb) \u00a0+4\r\n\r\nc) \u00a0+4\r\n\r\nd) \u00a0+2\r\n\r\ne) \u00a0\u22122\r\n\r\nf) \u00a0\u22123\r\n\r\n7.<\/strong>\r\n\r\nS8<\/sub> +\u00a08 O2<\/sub> \u2192\u00a08 SO2<\/sub>9.<\/strong>\r\n\r\n14 H+<\/sup> +\u00a0Cr2<\/sub>O7<\/sub>2\u2212<\/sup> +\u00a02 Fe \u2192\u00a02 Cr3+<\/sup> +\u00a07 H2<\/sub>O +\u00a02 Fe3+<\/sup>11.<\/strong>\r\n\r\n6 HN3<\/sub> +\u00a0UO2<\/sub>2+<\/sup> \u2192\u00a0U +\u00a02 H2<\/sub>O +\u00a09 N2<\/sub> +\u00a02 H+<\/sup>13.<\/strong>\r\n\r\nThe voltage of the reaction is +0.76 V, which implies a spontaneous reaction.\r\n\r\n15.<\/strong>\r\n\r\n3 Cr2+<\/sup> \u2192\u00a0Cr +\u00a02 Cr3+<\/sup>; \u22120.50 V\r\n\r\n17.<\/strong>\r\n\r\nCH4<\/sub> +\u00a02 O2<\/sub> \u2192\u00a0CO2<\/sub> +\u00a02 H2<\/sub>O\r\n\r\n19.<\/strong>\r\n\r\nyes because reduction occurs at the cathode\r\n\r\n21.<\/strong>\r\n\r\n0.318 g\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>","rendered":"
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    \n

    Additional Exercises<\/h3>\n

     <\/p>\n

      \n
    1. \n
      \n

      Oxidation was once defined as chemically adding oxygen to a substance. Use this reaction to argue that this definition is consistent with the modern definition of oxidation.<\/p>\n

      2 Mg +\u00a0O2<\/sub> \u2192\u00a02 MgO<\/span><\/span><\/p>\n<\/div>\n<\/li>\n

    2. \n
      \n

      Reduction was once defined as chemically adding hydrogen to a substance. Use this reaction to argue that this definition is consistent with the modern definition of reduction.<\/p>\n

      C2<\/sub>H2<\/sub> +\u00a02 H2<\/sub> \u2192\u00a0C2<\/sub>H6<\/sub><\/span><\/span><\/p>\n<\/div>\n<\/li>\n

    3. \n
      \n

      Assign oxidation numbers to the atoms in each substance.<\/p>\n<\/div>\n<\/li>\n<\/ol>\n

      a) \u00a0Kr (krypton)<\/p>\n

      b) \u00a0krypton tetrafluoride (KrF4<\/sub>)<\/p>\n

      c) \u00a0dioxygen difluoride (O2<\/sub>F2<\/sub>)<\/p>\n

       <\/p>\n

      \n

      4. \u00a0Assign oxidation numbers to the atoms in each substance.<\/p>\n

      a) \u00a0lithium hydride (LiH)<\/p>\n

      b) \u00a0potassium peroxide (K2<\/sub>O2<\/sub>)<\/p>\n

      c) \u00a0potassium fluoride (KF)<\/p>\n<\/div>\n

       <\/p>\n

      \n

      5. \u00a0N atoms can have a wide range of oxidation numbers. Assign oxidation numbers for the N atom in each compound, all of which are known compounds.<\/p>\n

      a) \u00a0N2<\/sub>O5<\/sub><\/p>\n

      b) \u00a0N2<\/sub>O4<\/sub><\/p>\n

      c) \u00a0NO2<\/sub><\/p>\n

      d) \u00a0NO<\/p>\n

      e) \u00a0N2<\/sub>H4<\/sub><\/p>\n

      f) \u00a0NH3<\/sub><\/p>\n<\/div>\n

       <\/p>\n

      \n

      6. \u00a0Cr atoms can have a wide range of oxidation numbers. Assign oxidation numbers for the Cr atom in each compound, all of which are known compounds.<\/p>\n

      a) \u00a0Na2<\/sub>CrO4<\/sub><\/p>\n

      b) \u00a0Na2<\/sub>Cr2<\/sub>O7<\/sub><\/p>\n

      c) \u00a0CrF5<\/sub><\/p>\n

      d) \u00a0CrCl3<\/sub><\/p>\n

      e) \u00a0CrCl2<\/sub><\/p>\n<\/div>\n

       <\/p>\n

      \n

      7. \u00a0Balance this redox reaction by inspection.<\/p>\n

      S8<\/sub> +\u00a0O2<\/sub> \u2192\u00a0SO2<\/sub><\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      8. \u00a0Balance this redox reaction by inspection.<\/p>\n

      C18<\/sub>H38<\/sub> +\u00a0O2<\/sub> \u2192\u00a0CO2<\/sub> +\u00a0H2<\/sub>O<\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      9. \u00a0Balance this redox reaction by the half reaction method by assuming an acidic solution.<\/p>\n

      Cr2<\/sub>O7<\/sub>2\u2212<\/sup> +\u00a0Fe \u2192\u00a0Cr3+<\/sup> +\u00a0Fe3+<\/sup><\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      10. \u00a0Balance the redox reaction in Exercise 9 by the half reaction method by assuming a basic solution.<\/p>\n<\/div>\n

       <\/p>\n

      \n

      11. \u00a0The uranyl ion (UO2<\/sub>2+<\/sup>) is a fairly stable ion of uranium that requires strong reducers to reduce the oxidation number of uranium further. Balance this redox reaction using the half reaction method by assuming an acidic solution.<\/p>\n

      UO2<\/sub>2+<\/sup> +\u00a0HN3<\/sub> \u2192\u00a0U +\u00a0N2<\/sub><\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      12. \u00a0Balance the redox reaction in Exercise 11 by the half reaction method by assuming a basic solution.<\/p>\n<\/div>\n

       <\/p>\n

      \n

      13. \u00a0Zinc metal can be dissolved by acid, which contains H+<\/sup> ions. Demonstrate that this is consistent with the fact that this reaction has a spontaneous voltage:<\/p>\n

      Zn +\u00a02 H+<\/sup> \u2192\u00a0Zn2+<\/sup> +\u00a0H2<\/sub><\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      14. \u00a0Copper metal cannot be dissolved by acid, which contains H+<\/sup> ions. Demonstrate that this is consistent with the fact that this reaction has a nonspontaneous voltage:<\/p>\n

      Cu +\u00a02 H+<\/sup> \u2192\u00a0Cu2+<\/sup> +\u00a0H2<\/sub><\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      15. \u00a0A disproportionation reaction occurs when a single reactant is both oxidized and reduced. Balance and determine the voltage of this disproportionation reaction. Use the data in Table 14.1 “Standard Reduction Potentials of Half Reactions”<\/a>.<\/p>\n

      Cr2+<\/sup> \u2192\u00a0Cr +\u00a0Cr3+<\/sup><\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      16. \u00a0A disproportionation reaction occurs when a single reactant is both oxidized and reduced. Balance and determine the voltage of this disproportionation reaction. Use the data in Table 14.1 “Standard Reduction Potentials of Half Reactions”<\/a>.<\/p>\n

      Fe2+<\/sup> \u2192\u00a0Fe +\u00a0Fe3+<\/sup><\/span><\/span><\/p>\n<\/div>\n

       <\/p>\n

      \n

      17. \u00a0What would be overall reaction for a fuel cell that uses CH4<\/sub> as the fuel?<\/p>\n<\/div>\n

       <\/p>\n

      \n

      18. \u00a0What would be overall reaction for a fuel cell that uses gasoline (general formula C8<\/sub>H18<\/sub>) as the fuel?<\/p>\n<\/div>\n

       <\/p>\n

      \n

      19. \u00a0When NaCl undergoes electrolysis, sodium appears at the cathode. Is the definition of cathode the same for an electrolytic cell as it is for a voltaic cell?<\/p>\n<\/div>\n

       <\/p>\n

      \n

      20. \u00a0When NaCl undergoes electrolysis, chlorine appears at the anode. Is the definition of anode the same for an electrolytic cell as it is for a voltaic cell?<\/p>\n<\/div>\n

       <\/p>\n

      \n

      21. \u00a0An award is being plated with pure gold before it is presented to a recipient. If the area of the award is 55.0 cm2<\/sup> and will be plated with 3.00 \u00b5m of Au, what mass of Au will be plated on the award? The density of Au is 19.3 g\/cm3<\/sup>.<\/p>\n<\/div>\n

       <\/p>\n

      \n

      22. \u00a0The unit of electrical charge is called the coulomb (C). It takes 96,500 coulombs of charge to reduce 27.0 g of Al from Al3+<\/sup> to Al metal. At 1,040 cm3<\/sup>, how many coulombs of charge were needed to reduce the aluminum in the cap of the Washington monument, assuming the cap is pure Al? The density of Al is 2.70 g\/cm3<\/sup>.<\/p>\n<\/div>\n<\/div>\n<\/div>\n

      \n
      \n

      Answers<\/h3>\n

      1.<\/strong><\/p>\n

      As oxygen is added to magnesium, it is being oxidized. In modern terms, the Mg atoms are losing electrons and being oxidized, while the electrons are going to the O atoms.<\/p>\n

      3.<\/strong><\/p>\n

      a) \u00a0Kr: 0<\/p>\n

      b) \u00a0Kr: +4; F: \u22121<\/p>\n

      c) \u00a0O: +1; F: \u22121<\/p>\n

      5.<\/strong><\/p>\n

      a) \u00a0+5<\/p>\n

      b) \u00a0+4<\/p>\n

      c) \u00a0+4<\/p>\n

      d) \u00a0+2<\/p>\n

      e) \u00a0\u22122<\/p>\n

      f) \u00a0\u22123<\/p>\n

      7.<\/strong><\/p>\n

      S8<\/sub> +\u00a08 O2<\/sub> \u2192\u00a08 SO2<\/sub>9.<\/strong><\/p>\n

      14 H+<\/sup> +\u00a0Cr2<\/sub>O7<\/sub>2\u2212<\/sup> +\u00a02 Fe \u2192\u00a02 Cr3+<\/sup> +\u00a07 H2<\/sub>O +\u00a02 Fe3+<\/sup>11.<\/strong><\/p>\n

      6 HN3<\/sub> +\u00a0UO2<\/sub>2+<\/sup> \u2192\u00a0U +\u00a02 H2<\/sub>O +\u00a09 N2<\/sub> +\u00a02 H+<\/sup>13.<\/strong><\/p>\n

      The voltage of the reaction is +0.76 V, which implies a spontaneous reaction.<\/p>\n

      15.<\/strong><\/p>\n

      3 Cr2+<\/sup> \u2192\u00a0Cr +\u00a02 Cr3+<\/sup>; \u22120.50 V<\/p>\n

      17.<\/strong><\/p>\n

      CH4<\/sub> +\u00a02 O2<\/sub> \u2192\u00a0CO2<\/sub> +\u00a02 H2<\/sub>O<\/p>\n

      19.<\/strong><\/p>\n

      yes because reduction occurs at the cathode<\/p>\n

      21.<\/strong><\/p>\n

      0.318 g<\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\t\t\t

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