{"id":7386,"date":"2021-06-08T21:56:02","date_gmt":"2021-06-08T21:56:02","guid":{"rendered":"https:\/\/opentextbc.ca\/introductorychemistry\/chapter\/end-of-chapter-7-material\/"},"modified":"2021-09-24T21:18:34","modified_gmt":"2021-09-24T21:18:34","slug":"end-of-chapter-7-material","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/introductorychemistry\/chapter\/end-of-chapter-7-material\/","title":{"raw":"End-of-Chapter Material","rendered":"End-of-Chapter Material"},"content":{"raw":"[latexpage]\r\n
\r\n

Additional Exercises<\/p>\r\n\r\n<\/header>\r\n

\r\n
    \r\n \t
  1. What is the work when 124 mL of gas contract to 72.0 mL under an external pressure of 822 torr?<\/li>\r\n \t
  2. What is the work when 2,345 mL of gas contract to 887 mL under an external pressure of 348 torr?<\/li>\r\n \t
  3. A 3.77 L volume of gas is exposed to an external pressure of 1.67 atm. As the gas contracts, 156 J of work are added to the gas. What is the final volume of the gas?<\/li>\r\n \t
  4. A 457 mL volume of gas contracts when 773 torr of external pressure act on it. If 27.4 J of work are added to the gas, what is its final volume?<\/li>\r\n \t
  5. What is the heat when 1,744 g of Hg increase in temperature by 334\u00b0C? Express your final answer in kJ.<\/li>\r\n \t
  6. What is the heat when 13.66 kg of Fe cool by 622\u00b0C? Express your final answer in kJ.<\/li>\r\n \t
  7. What is final temperature when a 45.6 g sample of Al at 87.3\u00b0C gains 188 J of heat?<\/li>\r\n \t
  8. What is final temperature when 967 g of Au at 557\u00b0C lose 559 J of heat?<\/li>\r\n \t
  9. Plants take CO2<\/sub> and H2<\/sub>O and make glucose (C6<\/sub>H12<\/sub>O6<\/sub>) and O2<\/sub>. Write a balanced thermochemical equation for this process. Use data in Table 7.1 \"Enthalpies of Formation for Various Substances.\"<\/a><\/li>\r\n \t
  10. Exercise 9 described the formation of glucose in plants, which take in CO2<\/sub> and H2<\/sub>O and give off O2<\/sub>. Is this process exothermic or endothermic? If exothermic, where does the energy go? If endothermic, where does the energy come from?<\/li>\r\n \t
  11. The basic reaction in the refining of aluminum is to take Al2<\/sub>O3<\/sub>(s) and turn it into Al(s) and O2<\/sub>(g). Write the balanced thermochemical equation for this process. Use data in Table 7.1.<\/li>\r\n \t
  12. Is the enthalpy change of the reaction H2<\/sub>O(\u2113) \u2192\u00a0H2<\/sub>O(g) zero or nonzero? Use data in Table 7.1 to determine the answer.<\/li>\r\n \t
  13. What mass of H2<\/sub>O can be heated from 22\u00b0C to 80\u00b0C in the combustion of 1 mol of CH4<\/sub>? You will need the balanced thermochemical equation for the combustion of CH4<\/sub>. Use data in Table 7.1.<\/li>\r\n \t
  14. What mass of H2<\/sub>O can be heated from 22\u00b0C to 80\u00b0C in the combustion of 1 mol of C2<\/sub>H6<\/sub>? You will need the balanced thermochemical equation for the combustion of C2<\/sub>H6<\/sub>. Use data in Table 7.1. Compare your answer to Exercise 13.<\/li>\r\n \t
  15. What is the enthalpy change for the unknown reaction?\r\n

    [latex]\\begin{align*}\r\n\\ce{Pb(s)}+\\ce{Cl2(g)}&\\rightarrow\\ce{PbCl2(s)} & \\Delta H&=-359\\text{ kJ} \\\\\r\n\\ce{PbCl2(s)}+\\ce{Cl2(g)}&\\rightarrow \\ce{PbCl4(\\ell)} & \\Delta H&=? \\\\\r\n\\ce{Pb(s)}+\\ce{2Cl2(g)}&\\rightarrow \\ce{PbCl4(\\ell)} & \\Delta H&=-329\\text{ kJ}\r\n\\end{align*}[\/latex]<\/p>\r\n<\/li>\r\n \t

  16. What is the enthalpy change for the unknown reaction?\r\n

    [latex]\\begin{align*}\r\n\\ce{P(s)}+\\ce{\\dfrac{3}{2}Br2(\\ell)}&\\rightarrow \\ce{PBr3(\\ell)} & \\Delta H&=-185\\text{ kJ} \\\\\r\n\\ce{PI3(s)}&\\rightarrow \\ce{P(s)}+\\ce{\\dfrac{3}{2}I2(s)} & \\Delta H&=? \\\\\r\n\\ce{PI3}+\\ce{\\dfrac{3}{2}Br2(\\ell)}&\\rightarrow \\ce{PBr3(\\ell)}+\\ce{\\dfrac{3}{2}I2(s)} & \\Delta H&=-139\\text{ kJ}\r\n\\end{align*}[\/latex]<\/p>\r\n<\/li>\r\n \t

  17. What is the \u0394H<\/i> for the reaction C(s, gra) \u2192 C(s, dia)? The label gra<\/i> means graphite, and the label dia<\/i> means diamond. What does your answer mean?<\/li>\r\n \t
  18. Without consulting any tables, determine the \u0394H<\/i> for the reaction H2<\/sub>O(\u2113, 25\u00b0C) \u2192\u00a0H2<\/sub>O(\u2113, 25\u00b0C). Explain your answer.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
    \r\n

    Answers<\/p>\r\n\r\n<\/header>\r\n

    \r\n
      \r\n \t
    1. 5.70 J<\/li>\r\n<\/ol>\r\n
        \r\n \t
      1. 4.69 L<\/li>\r\n<\/ol>\r\n
          \r\n \t
        1. 80.97 kJ<\/li>\r\n<\/ol>\r\n
            \r\n \t
          1. 91.9\u00b0C<\/li>\r\n<\/ol>\r\n
              \r\n \t
            1. [latex]\\ce{6CO2(g)}+\\ce{6H2O(\\ell)}\\rightarrow \\ce{C6H12O6(s)}+\\ce{6O2(g)}\\quad\\Delta H=2,799\\text{ kJ}[\/latex]<\/li>\r\n<\/ol>\r\n
                \r\n \t
              1. [latex]\\ce{2Al2O3(s)}\\rightarrow \\ce{4Al(s)}+\\ce{3O2(g)}\\quad\\Delta H=3,351.4\\text{ kJ}[\/latex]<\/li>\r\n<\/ol>\r\n
                  \r\n \t
                1. 3,668 g<\/li>\r\n<\/ol>\r\n
                    \r\n \t
                  1. \u0394H<\/i>\u00a0=\u00a030 kJ<\/li>\r\n<\/ol>\r\n
                      \r\n \t
                    1. \u0394H<\/i>\u00a0=\u00a01.897 kJ; the reaction is endothermic.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>","rendered":"
                      \n
                      \n

                      Additional Exercises<\/p>\n<\/header>\n

                      \n
                        \n
                      1. What is the work when 124 mL of gas contract to 72.0 mL under an external pressure of 822 torr?<\/li>\n
                      2. What is the work when 2,345 mL of gas contract to 887 mL under an external pressure of 348 torr?<\/li>\n
                      3. A 3.77 L volume of gas is exposed to an external pressure of 1.67 atm. As the gas contracts, 156 J of work are added to the gas. What is the final volume of the gas?<\/li>\n
                      4. A 457 mL volume of gas contracts when 773 torr of external pressure act on it. If 27.4 J of work are added to the gas, what is its final volume?<\/li>\n
                      5. What is the heat when 1,744 g of Hg increase in temperature by 334\u00b0C? Express your final answer in kJ.<\/li>\n
                      6. What is the heat when 13.66 kg of Fe cool by 622\u00b0C? Express your final answer in kJ.<\/li>\n
                      7. What is final temperature when a 45.6 g sample of Al at 87.3\u00b0C gains 188 J of heat?<\/li>\n
                      8. What is final temperature when 967 g of Au at 557\u00b0C lose 559 J of heat?<\/li>\n
                      9. Plants take CO2<\/sub> and H2<\/sub>O and make glucose (C6<\/sub>H12<\/sub>O6<\/sub>) and O2<\/sub>. Write a balanced thermochemical equation for this process. Use data in Table 7.1 “Enthalpies of Formation for Various Substances.”<\/a><\/li>\n
                      10. Exercise 9 described the formation of glucose in plants, which take in CO2<\/sub> and H2<\/sub>O and give off O2<\/sub>. Is this process exothermic or endothermic? If exothermic, where does the energy go? If endothermic, where does the energy come from?<\/li>\n
                      11. The basic reaction in the refining of aluminum is to take Al2<\/sub>O3<\/sub>(s) and turn it into Al(s) and O2<\/sub>(g). Write the balanced thermochemical equation for this process. Use data in Table 7.1.<\/li>\n
                      12. Is the enthalpy change of the reaction H2<\/sub>O(\u2113) \u2192\u00a0H2<\/sub>O(g) zero or nonzero? Use data in Table 7.1 to determine the answer.<\/li>\n
                      13. What mass of H2<\/sub>O can be heated from 22\u00b0C to 80\u00b0C in the combustion of 1 mol of CH4<\/sub>? You will need the balanced thermochemical equation for the combustion of CH4<\/sub>. Use data in Table 7.1.<\/li>\n
                      14. What mass of H2<\/sub>O can be heated from 22\u00b0C to 80\u00b0C in the combustion of 1 mol of C2<\/sub>H6<\/sub>? You will need the balanced thermochemical equation for the combustion of C2<\/sub>H6<\/sub>. Use data in Table 7.1. Compare your answer to Exercise 13.<\/li>\n
                      15. What is the enthalpy change for the unknown reaction?\n

                        \n

                          <\/span>   <\/span>\"\begin{align*}<\/p>\n<\/li>\n

                      16. What is the enthalpy change for the unknown reaction?\n

                        \n

                          <\/span>   <\/span>\"\begin{align*}<\/p>\n<\/li>\n

                      17. What is the \u0394H<\/i> for the reaction C(s, gra) \u2192 C(s, dia)? The label gra<\/i> means graphite, and the label dia<\/i> means diamond. What does your answer mean?<\/li>\n
                      18. Without consulting any tables, determine the \u0394H<\/i> for the reaction H2<\/sub>O(\u2113, 25\u00b0C) \u2192\u00a0H2<\/sub>O(\u2113, 25\u00b0C). Explain your answer.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n
                        \n
                        \n

                        Answers<\/p>\n<\/header>\n

                        \n
                          \n
                        1. 5.70 J<\/li>\n<\/ol>\n
                            \n
                          1. 4.69 L<\/li>\n<\/ol>\n
                              \n
                            1. 80.97 kJ<\/li>\n<\/ol>\n
                                \n
                              1. 91.9\u00b0C<\/li>\n<\/ol>\n
                                  \n
                                1. \"\ce{6CO2(g)}+\ce{6H2O(\ell)}\rightarrow \ce{C6H12O6(s)}+\ce{6O2(g)}\quad\Delta H=2,799\text{ kJ}\"<\/li>\n<\/ol>\n
                                    \n
                                  1. \"\ce{2Al2O3(s)}\rightarrow \ce{4Al(s)}+\ce{3O2(g)}\quad\Delta H=3,351.4\text{ kJ}\"<\/li>\n<\/ol>\n
                                      \n
                                    1. 3,668 g<\/li>\n<\/ol>\n
                                        \n
                                      1. \u0394H<\/i>\u00a0=\u00a030 kJ<\/li>\n<\/ol>\n
                                          \n
                                        1. \u0394H<\/i>\u00a0=\u00a01.897 kJ; the reaction is endothermic.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n","protected":false},"author":90,"menu_order":7,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-7386","chapter","type-chapter","status-publish","hentry"],"part":7374,"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/pressbooks\/v2\/chapters\/7386","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/wp\/v2\/users\/90"}],"version-history":[{"count":3,"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/pressbooks\/v2\/chapters\/7386\/revisions"}],"predecessor-version":[{"id":8811,"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/pressbooks\/v2\/chapters\/7386\/revisions\/8811"}],"part":[{"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/pressbooks\/v2\/parts\/7374"}],"metadata":[{"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/pressbooks\/v2\/chapters\/7386\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/wp\/v2\/media?parent=7386"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/pressbooks\/v2\/chapter-type?post=7386"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/wp\/v2\/contributor?post=7386"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/introductorychemistry\/wp-json\/wp\/v2\/license?post=7386"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}