Homework answers / question archive / Chapter 6: Quantities in Chemical Reactions 1)  When one molecule of propane, C3H8, burns in a gas grill, it combines with five oxygen molecules to form three CO2 molecules and four H2O molecules

Chapter 6: Quantities in Chemical Reactions 1)  When one molecule of propane, C3H8, burns in a gas grill, it combines with five oxygen molecules to form three CO2 molecules and four H2O molecules

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Chapter 6: Quantities in Chemical Reactions

1)  When one molecule of propane, C₃H₈, burns in a gas grill, it combines with five oxygen molecules to form three CO₂ molecules and four H₂O molecules.  Select the statement below that is incorrect in regard to this reaction.

            A)      The balanced equation for the reaction is C₃H₈ + 5O₂ ® 3CO₂ + 4H₂O.

            B)      If five propane molecules react, 15 CO₂ molecules will be formed.

            C)      If five propane molecules react, 25 O₂ molecules must also react.

            D)      If 15 O₂ molecules react, 9 H₂O molecules will be formed.

            E)      If 12 CO₂ molecules are formed, then four propane molecules must have reacted.

 

        2.  When ethanol, C₂H₅OH, a component in some gasoline mixtures, is burned in air, one molecule of ethanol combines with three oxygen molecules to form two CO₂ molecules and three H₂O molecules.  Select the statement below that is incorrect in regard to this reaction.

            A)      The balanced equation for the reaction is C₂H₅OH + 3O₂ ® 2CO₂ + 3H₂O.

            B)      If four ethanol molecules react, eight CO₂ molecules will be formed.

            C)      If 12 H₂O molecules are formed, then nine O₂ molecules must have reacted.

            D)      If  15 ethanol molecules react, then 45 oxygen molecules must also react.

            E)      If 12 CO₂ molecules are formed, then 18 H₂O molecules will also be formed.

 

        3.  When acetylene, C₂H₂, a fuel used in welding, is burned in air, two molecules of acetylene combine with five oxygen molecules to form four CO₂ molecules and two H₂O molecules.  Select the statement below that is incorrect in regard to this reaction.

            A)      The balanced equation for the reaction is 2C₂H₂ + 5O₂ ® 4CO₂ + 2H₂O.

            B)      If eight acetylene molecules react, 12 CO₂ molecules will be formed.

            C)      If 12 H₂O molecules are formed, then 30 O₂ molecules must have reacted.

            D)      If 12 CO₂ molecules are formed, then six H₂O molecules will also be formed.

            E)      If  24 ethanol molecules react, then 60 oxygen molecules must also react.

 

        4.  All of the following may change during a chemical reaction except

            A)      the total number of atoms in the system.

            B)      the temperature of the system.

            C)      the color of the system.

            D)      the total number of molecules in the system.

            E)      the physical state of the system.

 

        5.  When sodium sulfate, Na₂SO₄, dissolves in water, the ions that are formed for each formula unit that dissolves are:

            A)      Na₂²⁺(aq) + SO₄^2-(aq)                           D)      Na₂²⁺(aq) + S(s) + O₄^2-(aq)

            B)      2Na²⁺(aq) + SO₄^2-(aq)                          E)      Na₂²⁺(aq) + S^2-(aq) + 4O^2-(aq)

            C)      2Na⁺(aq) + SO₄^2-(aq)                                    

 

        6.  When potassium carbonate, K₂CO₃, dissolves in water, the ions that are formed for each formula unit that dissolves are:

            A)      K₂²⁺(aq) + CO₃^2-(aq)                            D)      2K⁺(aq) + C(s) + O₃^2-(aq)

            B)      2K²⁺(aq) + CO₃^2-(aq)                            E)      K₂²⁺(aq) + C⁴⁺(aq) + 3O^2-(aq)

            C)      2K⁺(aq) + CO₃^2-(aq)                                      

 

        7.  When ammonium carbonate, (NH₄)₂CO₃, dissolves in water, the ions that are formed for each formula unit that dissolves are:

            A)      (NH₄)₂²⁺(aq) + CO₃^2-(aq)

            B)      2NH₄⁺(aq) + CO₃^2-(aq)

            C)      2N^3-(aq) + 4H⁺(aq) + CO₃^2-(aq)

            D)      2N^3-(aq) + 4H⁺(aq) + C(s) + O₃^2-(aq)

            E)      2N^3-(aq) + 4H⁺(aq) + C⁴⁺(aq)+ 3O^2-(aq)

 

        8.  Which of the following is the best balanced equation to represent the chemical reaction exactly as shown in the figure?

           

            A)      4A + 8B ® 12AB                                 D)      A₂ + B₂ ® AB₂

            B)      2A₂ + 4B₂ ® 4A₂B                               E)      A₂ + 2B₂ ® 2AB₂

            C)      2A₂ + 4B₂ ® 4AB₂                                        

             9.         Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

           

            A)      16H + 10O ® 16H + 10O                    D)      2H₂ + O₂ ® 2H₂O

            B)      16H + 10O ® 8H₂O + O₂                    E)      4H₂ + 2O₂ ® 4H₂O

            C)      8H₂ + 5O₂ ® 8H₂O + O₂                               

      10.  Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

           

 

            A)      12N + 12H ® 12NH                            D)      12N + 12H ® 4NH₃ + 8N

            B)      6N₂ + 6H₂ ® 4NH₃                              E)      N₂ + 3H₂ ® 2NH₃

            C)      6N₂ + 6H₂ ® 4NH₃ + 4N₂                             

 

      11.  When the mixture of molecules shown in the molecular-level image undergoes complete reaction, all of these molecules are converted to products.  Which of the following reactions could this represent?

           

 

            A)      N₂ + O₂ ® 2NO                                    D)      N₂ + 3H₂ ® 2NH₃

            B)      N₂ + 2Cl₂ ® N₂Cl₄                                E)      N₂ + 3O₂ ® 2NO₃

            C)      N₂ + 2O₂ ® 2NO₂                                         

 

      12.  When the mixture of molecules shown in the molecular-level image undergoes complete reaction, all of these molecules are converted to products.  Which of the following reactions could this represent?

           

 

            A)      2N₂ + 3O₂ ® 2N₂O₃                             D)      N₂ + 3Cl₂ ® 2NCl₃

            B)      N₂ + 2Cl₂ ® N₂Cl₄                                E)      3N₂ + 2H₂ ® 3N₂H₄

            C)      O₂ + 2H₂ ® 2H₂O                                         

 

      13.  When mixed, solutions of aluminum nitrate, Al(NO₃)₃, and ammonium carbonate, (NH₄)₂CO₃, will form a precipitate of aluminum carbonate, Al₂(CO₃)₃. The balanced equation is:

            2Al(NO₃)₃(aq) + 3(NH₄)₂CO₃(aq) ® Al₂(CO₃)₃ (s) + 6NH₄NO₃(aq)

            Which of the following statements regarding this reaction is incorrect?

            A)      2 moles of Al(NO₃)₃ will react with 3 moles of (NH₄)₂CO₃.

            B)      If 6 moles of (NH₄)₂CO₃ react with sufficient Al(NO₃)₃, 2 moles of Al₂(CO₃)₃ will be formed.

            C)      If 0.5 mole of (NH₄)₂CO₃ react with sufficient Al(NO₃)₃, 3 moles of Al₂(CO₃)₃ will be formed.

            D)      If 1.5 moles of Al₂(CO₃)₃ are formed, given sufficient starting materials, then 9 moles of NH₄NO₃ will also be formed.

            E)      4 moles of Al(NO₃)₃ will react with 6 moles of (NH₄)₂CO₃.

 

      14.  When mixed, solutions of silver nitrate, AgNO₃, and sodium phosphate, Na₃PO₄, will form a precipitate of silver phosphate, Ag₃PO₄. The balanced equation is: 

            3AgNO₃(aq) + Na₃PO₄(aq) ®  Ag₃PO₄(s) + 3NaNO₃(aq)

            Which of the following statements regarding this reaction is incorrect?

            A)      6 moles of AgNO₃  will react with 2 moles of Na₃PO₄.

            B)      9 moles of AgNO₃  will form 2 moles of Ag₃PO₄, given sufficient Na₃PO₄.

            C)      1.5 moles of NaNO₃ will be formed when 0.5 mole of Na₃PO₄ reacts with sufficient AgNO₃.

            D)      3 moles of Ag₃PO₄ will be formed when 3 moles of Na₃PO₄ react with sufficient AgNO₃.

            E)      2 moles of Na₃PO₄ will react with 6 moles of AgNO₃.

 

      15.  When mixed, solutions of copper(II) nitrate, Cu(NO₃)₂, and sodium phosphate, Na₃PO₄, will form a precipitate of copper phosphate, Cu₃(PO₄)₂. The balanced equation is:

            3Cu(NO₃)₂(aq)  + 2Na₃PO₄(aq) ®  Cu₃(PO₄)₂(s) + 6NaNO₃(aq)

             Which of the following statements regarding this reaction is incorrect?

            A)      8 moles of Na₃PO₄ will react with 12 moles of  Cu(NO₃)₂.

            B)      1 mole of NaNO₃ will be formed when 0.5 mole of Cu(NO₃)₂  reacts with sufficient Na₃PO₄.

            C)      12 moles of Cu₃(PO₄)₂ will be formed when 36 moles of Cu(NO₃)₂  reacts with sufficient Na₃PO₄.

            D)      If 10 moles of Na₃PO₄ react with sufficient Cu(NO₃)₂, 4 moles of Cu₃(PO₄)₂ will be formed.

            E)      If 5 moles of Cu₃(PO₄)₂ are needed, it would require the combination of 15 moles of Cu(NO₃)₂  and 10 moles of  Na₃PO₄.

 

      16.  Consider the reaction between hydrogen and oxygen gases to form water:

            2H₂(g) + O₂(g) ®  2H₂O(l)

            Which of the following is not conserved in this reaction?

            A)      atoms

            B)      moles of atoms

            C)      mass

            D)      both moles of molecules and moles of atoms

            E)      moles of molecules

 

      17.  Consider the reaction between sodium metal and chlorine gas to form sodium chloride:

            2Na(s) + Cl₂(g) ®  2NaCl(s)

            Which of the following is not conserved in this reaction?

            A)      atoms

            B)      moles of atoms

            C)      mass

            D)      both moles of molecules and moles of atoms

            E)      moles of molecules

 

      18.  Consider the reaction between acetylene, C₂H₂, and oxygen in a welding torch:

            2C₂H₂(g) + 5O₂(g) ® 4CO₂(g) + 2H₂O(g)

            Which of the following is not conserved in this reaction?

            A)      atoms

            B)      moles of atoms

            C)      mass

            D)      both moles of molecules and moles of atoms

            E)      moles of molecules

      19.  Which of the following equations is balanced?

            A)      P₄(s) + 10O₂(g) ® P₄O₁₀(s)

            B)      ZnS(s) + 3O₂(g) ® ZnO(s) + 2SO₂(g)

            C)      NH₃(g) + O₂(g) ® NO₂(g) + H₂O(g)

            D)      4KBrO₃(s) ® 3KBrO₄(s) + KBr(s)

            E)      2Na(s) + P(s) ® Na₃P(s)

 

      20.  Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows:

            4PH₃(g) + 8O₂(g) ® P₄O₁₀(s) + 6H₂O(g)

            If 9.2 moles of phosphine react with sufficient oxygen, how many moles of P₄O₁₀ will be formed?

            A)  4.0 moles    B)  9.2 moles    C)  37 moles    D)  2.3 moles    E)  6.0 moles

 

      21.  Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows:

            4PH₃(g) + 8O₂(g) ® P₄O₁₀(s) + 6H₂O(g)

            If you need to make 6.5 moles of P₄O₁₀ , how many moles of PH₃ would be required for the reaction?

            A)  6.5 moles    B)  13 moles    C)  26 moles    D)  3.2 moles    E)  1.6 moles

 

      22.  Given that 4NH₃(g) + 5O₂(g) ® 4NO(g) + 6H₂O(g), if 6.3 moles of NH₃ react with sufficient oxygen, how many moles of NO will be formed?

            A)  4.0 moles    B)  6.3 moles    C)  6.0 moles    D)  5.0 moles    E)  3.2 moles

 

      23.  Given that 4NH₃(g) + 5O₂(g) ® 4NO(g) + 6H₂O(g), if 8.2 moles of NH₃ react with sufficient oxygen, how many moles of water will be formed?

            A)  6.0 moles    B)  4.0 moles    C)  5.0 moles    D)  12 moles    E)  8.2 moles

 

      24.  Given that 4NH₃(g) + 5O₂(g) ® 4NO(g) + 6H₂O(g), if 4.5 moles of NH₃ react with sufficient oxygen, how many moles of H₂O will be formed?

            A)  4.0    B)  4.5    C)  6.0    D)  6.8    E)  5.5

 

      25.  Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt):

            2Na(s) + Cl₂(g) ®  2NaCl(s)

            If 3.6 moles of chlorine react with sufficient sodium, how many grams of sodium chloride will be formed?

            A)  1.1 ´ 10² g    B)  2.1 ´ 10² g    C)  4.2 ´ 10² g    D)  0.13 g    E)  0.062 g

 

      26.  Consider the reaction between acetylene, C₂H₂, and oxygen in a welding torch:

            2C₂H₂(g) + 5O₂(g) ® 4CO₂(g) + 2H₂O(g)

            If 5.4 moles of acetylene react with sufficient oxygen, how many grams of CO₂ will be formed?

            A)  2.4 ´ 10² g    B)  9.5 ´ 10² g    C)  4.8 ´ 10² g    D)  1.5 ´ 10² g    E)  0.49 g

 

      27.  Consider the reaction between hydrogen and oxygen gases to form water:

            2H₂(g) + O₂(g) ®  2H₂O(l)

            If 8.5 moles of oxygen react with sufficient hydrogen, how many grams of water will be formed?

            A)  0.94 g    B)  0.47 g    C)  76 g    D)  3.1 ´ 10² g    E)  1.5 ´ 10² g

 

      28.  Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows:

            4PH₃(g) + 8O₂(g) ® P₄O₁₀(s) + 6H₂O(g)

            If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P₄O₁₀ will be formed?

            A)  125 g    B)  31.3 g    C)  5.00 ´ 10² g    D)  18.9 g    E)  75.7 g

 

      29.  Given that 4NH₃(g) + 5O₂(g) ® 4NO(g) + 6H₂O(g), if 82.0 g of NH₃ react with sufficient oxygen, how many grams of NO will be formed?

            A)  145 g    B)  5.80 ´ 10² g    C)  46.5 g    D)  186 g    E)  11.6 g

 

      30.  Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt):

            2Na(s) + Cl₂(g) ®  2NaCl(s)

            If 12.5 g of sodium react with sufficient chlorine, how many grams of sodium chloride will be formed?

            A)  15.9 g    B)  31.8 g    C)  63.6 g    D)  4.92 g    E)  9.84 g

 

      31.  Given that 4NH₃(g) + 5O₂(g) ® 4NO(g) + 6H₂O(g), if 32.5 g of NH₃ react with sufficient oxygen, how many grams of H₂O will be formed?

            A)  51.6 g    B)  8.60 g    C)  34.4 g    D)  206.4 g    E)  878 g

      32.  When copper reacts with sulfur at high temperature, copper(I) sulfide is formed.

            2Cu(s) + S(s) ®  Cu₂S(s)

            If the mass of the copper increases by 0.235 g, how many grams of copper reacted?

            A)  0.931 g    B)  not enough information    C)  958 g    D)  15.1 g    E)  0.471

 

      33.  When magnesium is heated in air, it reacts with oxygen to form magnesium oxide.

            2Mg(s) + O₂(g) ®  2MgO(s)

            If the mass of the magnesium increases by 0.335 g, how many grams of magnesium reacted?

            A)  0.882 g    B)  0.441 g    C)  0.509 g    D)  1.02 g    E)  not enough information

 

      34.  Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt):

            2Na(s) + Cl₂(g) ®  2NaCl(s)

            If the mass of the sodium increases by 0.500 g, how many grams of sodium reacted?

            A)  0.250 g    B)  0.500 g    C)  0.0811 g    D)  0.162 g    E)  0.324 g

 

      35.  When a 0.525 g piece of zinc is placed in a solution of copper(II) sulfate, copper metal and zinc sulfate are formed.  Balance the equation for the reaction, and determine the mass of copper(II) sulfate that would react with this quantity of zinc.

            ___ Zn(s) + ___CuSO₄(aq) ®  _{____}ZnSO₄(aq) + ___Cu(s)

            A)  65.4 g    B)  0.641 g    C)  1.28 g    D)  2.56 g    E)  159 g

 

      36.  Small amounts of oxygen gas can be produced for laboratory use by heating potassium chlorate, which causes it to decompose by the following reaction:

            ___KClO₃(s) ®  _{____}KCl(s) + ___O₂(g)   (unbalanced)

            Balance the equation, and determine the mass of oxygen that will be formed if 10.0 g of potassium chlorate decomposes.

            A)  7.83 g    B)  115 g    C)  3.92 g    D)  38.3 g    E)  57.4 g

 

      37.  Small amounts of oxygen gas can be produced for laboratory use by heating potassium chlorate, which causes it to decompose by the following reaction:

            ___KClO₃(s) ®  _{____}KCl(s) + ___O₂(g)   (unbalanced)

            Balance the equation, and determine the mass of oxygen that will be formed if 15.0 g of potassium chlorate decomposes.

            A)  11.7 g    B)  57.5 g    C)  173 g    D)  5.88 g    E)  86.1 g

      38.  When mercury(II) oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the equation:

            ___HgO(s) ® ___Hg(l) + ___O₂(g)  (unbalanced)

            Balance the equation and determine the mass of mercury that will be formed when 12.3 g of HgO is heated.

            A)  22.8 g    B)  11.4 g    C)  5.70 g    D)  13.3 g    E)  6.64 g

 

      39.  When mercury(II) oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the equation:

            ___HgO(s) ® ___Hg(l) + ___O₂(g)  (unbalanced)

            Balance the equation and determine the mass of mercury that will be formed when 15.6 g of HgO is heated.

            A)  28.9 g    B)  7.22 g    C)  14.4 g    D)  16.9 g    E)  13.2 g

 

      40.  When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation:

            ___P₄(s) + ___Cl₂(g)  ® ___PCl₃(l) (unbalanced)

            Balance the equation and determine how many grams of chlorine would be required to react with 10.6 g of phosphorus.

            A)  6.07 g    B)  24.3 g    C)  36.4 g    D)  18.5 g    E)  74.1 g

 

      41.  When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation:

            ___P₄(s) + ___Cl₂(g) ® ___PCl₃(l) (unbalanced)

            Balance the equation and determine how many grams of chlorine would be required to react with 21.2 g of phosphorus.

            A)  12.1 g    B)  48.6 g    C)  37.0 g    D)  148 g    E)  72.8 g

 

      42.  Nitrogen and hydrogen react together to form ammonia according to the equation:

            ___N₂(g) + ___H₂(g)  ® ___NH₃(g)  (unbalanced)

            Balance the equation, and determine how many grams of hydrogen would be required to react with 25.2 g of nitrogen.

            A)  1.82 g    B)  3.64 g    C)  5.45 g    D)  1.34 g    E)  0.891

 

      43.  Nitrogen and hydrogen react together to form ammonia according to the equation:

            ___N₂(g) + ___H₂(g)  ® ___NH₃(g)  (unbalanced)

            Balance the equation, and determine how many grams of hydrogen would be required to react with 50.4 g of nitrogen.

            A)  10.9 g    B)  3.64 g    C)  7.28 g    D)  2.68 g    E)  1.78 g

 

      44.  When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation:

            ___P₄(s) + ___Cl₂(g) ® ___PCl₃(l) (unbalanced)

            Balance the equation and determine how many grams of phosphorus would be required to form 25.0 g of phosphorus trichloride, assuming there is sufficient chlorine available.

            A)  22.6 g    B)  45.1 g    C)  5.64 g    D)  111 g    E)  90.2 g

 

      45.  When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation:

            ___P₄(s) + ___Cl₂(g) ® ___PCl₃(l) (unbalanced)

            Balance the equation and determine how many grams of phosphorus would be required to form 75.0 g of phosphorus trichloride, assuming there is sufficient chlorine available.

            A)  67.8 g    B)  135 g    C)  16.9 g    D)  271 g    E)  333 g

 

      46.  Nitrogen and hydrogen react together to form ammonia according to the equation:

            ___N₂(g) + ___H₂(g) ® ___NH₃(g) (unbalanced)

            Balance the equation, and determine how many grams of hydrogen would be required to form 50.0 g of ammonia, assuming there is sufficient nitrogen available.

            A)  4.46 g    B)  5.94 g    C)  4.81 g    D)  8.91 g    E)  not enough information

 

      47.  Nitrogen and hydrogen react together to form ammonia according to the equation:

            ___N₂(g) + ___H₂(g) ® ___NH₃(g) (unbalanced)

            Balance the equation, and determine how many grams of hydrogen would be required to form 25.0 g of ammonia, assuming there is sufficient nitrogen available.

            A)  2.23 g    B)  4.46 g    C)  2.97 g    D)  2.40 g    E)  not enough information

 

      48.  If you have eight bicycle wheels and five frames, how many bikes could you build (assuming that each bike requires one frame and two wheels), and what would be left over?

            A)      Four bikes could be built, and nothing would be left over.

            B)      Four bikes could be built, and one frame would be left over.

            C)      Five bikes could be built, and three wheels would be left over.

            D)      Five bikes could be built, and nothing would be left over.

            E)      Three bikes could be built, and two frames would be left over.

 

      49.  If you wish to make sandwiches which consist of two slices of bread, one ham slice, and three pickle slices, how many sandwiches could you make if you have 12 slices of bread, five slices of ham, and 20 pickle slices, and what would be left over?

            A)      Six sandwiches could be made, and two pickle slices would be left over.

            B)      Four sandwiches could be made, and four slices of bread and eight pickle slices would be left over.

            C)      Five sandwiches could be made, and two slices of bread and five pickle slices would be left over.

            D)      Twelve sandwiches could be made, and there would be no leftovers.

            E)      Five sandwiches could be made, and two slices of bread and no pickle slices would be left over.

 

      50.  A pamphlet requires one cover, 14 pieces of white paper, and three sheets of colored paper.   How many pamphlets could be made, and what would be left over, if there are 50 covers, 500 sheets of white paper, and 100 sheets of colored paper available?

            A)      33 pamphlets could be made, and one sheet of colored paper, 38 sheets of white paper, and 17 covers would be left over.

            B)      50 pamphlets could be made, and there would be no leftovers.

            C)      650 pamphlets could be made, and there would be no leftovers.

            D)      34 pamphlets could be made, and 24 sheets of white paper and 16 covers would be left over.

            E)      35 pamphlets could be made, and 10 sheets of white paper and 15 covers would be left over.

 

      51.  Consider the following reaction.

            CrCl₃(s) + KCl(s) + 2H₂SO₄(l)  ®  KCr(SO₄)₂(s) + 4HCl(g)

            green        white      colorless            purple              colorless

            solid          solid         liquid              solid                 gas

                  

            When the green solid is mixed with the white solid and the colorless liquid is added, the mixture starts to bubble and fume.  When all action has stopped, a wet purple solid containing solid white specks remains.  Which substance is the limiting reactant?

            A)  CrCl₃    B)  KCl    C)  H₂SO₄    D)  KCr(SO₄)₂    E)  HCl

 

      52.  Consider the following reaction.

            Cr₂O₃(s) +  3CCl₄(l) ® 2CrCl₃(s) + 3COCl₂(g)

            green        colorless         purple          colorless

            solid         liquid              solid             gas

            When the green solid is mixed with the colorless liquid, the mixture starts to bubble and fume.  When all action has stopped, a dry purple solid containing solid green specks remains.  Which substance is the limiting reactant?

            A)  Cr₂O₃    B)  CCl₄    C)  CrCl₃    D)  COCl₂    E)  there is no limiting reactant

 

      53.  Consider the following reaction.

            Cr₂O₃(s) +  3CCl₄(l) ® 2CrCl₃(s) + 3COCl₂(g)

            green        colorless         purple          colorless

            solid         liquid              solid             gas

            When the green solid is mixed with the colorless liquid, the mixture starts to bubble and fume.  When all action has stopped, a wet purple solid remains.  Which substance is the limiting reactant?

            A)  Cr₂O₃    B)  CCl₄    C)  CrCl₃    D)  COCl₂    E)  there is no limiting reactant

      54.  Phosphorus trichloride can be made by the reaction:

            P₄(s) + 6Cl₂(g) ® 4PCl₃(l)

            What is the maximum amount of phosphorus trichloride that can be formed if 10 molecules of P₄ react with 36 molecules of chlorine?

            A)      4 molecules                                            D)      24 molecules

            B)      6 molecules                                            E)      46 molecules

            C)      12 molecules                                                  

 

      55.  Phosphorus trichloride can be made by the reaction:

            P₄(s) + 6Cl₂(g) ® 4PCl₃(l)

            What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P₄ react with 42 molecules of chlorine?

            A)      4 molecules                                            D)      28 molecules

            B)      12 molecules                                          E)      57 molecules

            C)      24 molecules                                                  

 

      56.  Ammonia is usually made by the reaction:

            N₂(g) + 3H₂(g) ® 2NH₃(g)

            What is the maximum amount of ammonia that can be formed if 25 molecules of nitrogen react with 60 molecules of hydrogen?

            A)      20 molecules                                          D)      40 molecules

            B)      25 molecules                                          E)      85 molecules

            C)      30 molecules                                                  

 

      57.  Ammonia is usually made by the reaction:

            N₂(g) + 3H₂(g) ® 2NH₃(g)

            What is the maximum amount of ammonia that can be formed if 30 molecules of nitrogen react with 100 molecules of hydrogen?

            A)      20 molecules                                          D)      60 molecules

            B)      30 molecules                                          E)      70 molecules

            C)      40 molecules                                                  

      58.  The figure shows a molecular-level diagram of reactant molecules

           

 

            for the reaction: 2H₂(g) + O₂(g) ®  2H₂O(l)

            List the number and formulas of the molecules that will be present after the reaction takes place.

            A)      2H₂O + 6H₂ + 2O₂                                D)      6H₂O + 2H₂ + O₂

            B)      3H₂O + 5H₂ + O₂                                  E)      6H₂O + 2H₂

            C)      4H₂O + 4H₂ + O₂                                           

 

      59.  The figure shows a molecular-level diagram of reactant molecules

           

 

             for the reaction:

            2C₂H₂(g) + 5O₂(g) ® 4CO₂(g) + 2H₂O(g)

            List the number and formulas of the molecules that will be present after the reaction takes place.

            A)      4CO₂ + 2H₂O                                        D)      6CO₂ + 3H₂O + 3O₂

            B)      4CO₂ + 2H₂O + 2C₂H₂                         E)      8CO₂ + 4H₂O + 2C₂H₂

            C)      4CO₂ + 2H₂O + 2C₂H₂ + 5O₂                        

 

      60.  Consider the reaction, N₂(g) + O₂(g) ® 2NO(g)

            The molecular image represents a mixture of N₂(g) and O₂(g) just before reaction occurs.

            What is the limiting reactant and how much of the excess reactant remains after the reaction is complete?   The image contains 2 N₂ molecules and 4 O₂ molecules.

           

 

            A)      N₂(g), 1 O₂(g)                                        D)      O₂(g), 1 N₂(g)

            B)      N₂(g), 2 O₂(g)                                        E)      N₂(g), 0 O₂(g)

            C)      N₂(g), 3 O₂(g)                                                 

 

      61.  Consider the reaction, N₂(g) + 2O₂(g) ® 2NO₂(g)

            The molecular image represents a mixture of N₂(g) and O₂(g) just before reaction occurs.

            What is the limiting reactant and how much of the excess reactant remains after the reaction is complete?   The image contains 3 N₂ molecules and 9 O₂ molecules.

           

 

            A)      N₂(g), 6 O₂(g)                                        D)      O₂(g), 2 N₂(g)

            B)      O₂(g), 1 N₂(g)                                        E)      N₂(g), 7 O₂(g)

            C)      N₂(g), 3 O₂(g)                                                 

 

      62.  Nitrogen monoxide reacts with oxygen according to the reaction:

            2NO(g)  + O₂(g) ® 2NO₂(g)

            If 12 moles of nitrogen monoxide react with 10 moles of oxygen, how many moles of NO₂ will be formed?

            A)  2 moles    B)  5 moles    C)  6 moles    D)  10 moles    E)  12 moles

 

      63.  Nitrogen monoxide reacts with oxygen according to the reaction:

            2NO(g)  + O₂(g) ® 2NO₂(g)

            If 10 moles of nitrogen monoxide react with 4 moles of oxygen, how many moles of NO₂ will be formed?

            A)  4 moles    B)  8 moles    C)  10 moles    D)  12 moles    E)  14 moles

 

      64.  Aluminum reacts with oxygen according to the reaction:

            4Al(s) + 3O₂(g) ® 2Al₂O₃(s)

            If 24 moles of aluminum react with 12 moles of oxygen, how many moles of Al₂O₃ will be formed?

            A)  4.0 moles    B)  8.0 moles    C)  6.0 moles    D)  5.0 moles    E)  26 moles

 

      65.  Aluminum reacts with oxygen according to the reaction:

            4Al(s) + 3O₂(g) ® 2Al₂O₃(s)

            If 12 moles of aluminum react with 6 moles of oxygen, how many moles of Al₂O₃ will be formed?

            A)  4 moles    B)  8 moles    C)  6 moles    D)  12 moles    E)  20 moles

 

      66.  Consider the following reaction:

            3NO₂(g) + H₂O(l) ® 2HNO₃(l) + NO(g)

            How many moles of NO₂ are required to react with 1.50 moles of H₂O to form 3.00 moles of HNO₃?

            A)  1.50 mol    B)  3.00 mol    C)  4.00 mol    D)  4.50 mol    E)  9.00 mol

      67.  Consider the following reaction:

            3NO₂(g) + H₂O(l) ® 2HNO₃(l) + NO(g)

            How many moles of the excess reactant remain if 4.00 moles of H₂O and 10.00 moles of NO₂ are mixed?

            A)      0.67 mol H₂O                                        D)      6.00 mol NO₂

            B)      2.00 mol NO₂                                        E)      8.00 mol NO₂

            C)      3.33 mol H₂O                                                 

 

      68.  Iron metal reacts with chlorine gas according to the equation:

            2Fe(s) + 3Cl₂(g) ® 2FeCl₃(s)

            If 35.0 g each of iron and chlorine react, how much FeCl₃ will be formed?

            A)  102 g    B)  155 g    C)  53.4 g    D)  80.0 g    E)  68.0 g

      69.  Iron metal reacts with chlorine gas according to the equation:

            2Fe(s) + 3Cl₂(g) ® 2FeCl₃(s)

            If 25.6 g each of iron and chlorine react, how much FeCl₃ will be formed?

            A)  74.3 g    B)  113 g    C)  39.0 g    D)  49.5 g    E)  26.0 g

 

      70.  In the process of obtaining lead from PbS, or galena, the galena is “roasted” (heated in the presence of oxygen), so that the following reaction occurs:

            2PbS(s) + 3O₂(g) ® 2PbO(s)  + 2SO₂(g)

            If 50.0 g of PbS reacts with 25.0 g of oxygen, how many grams of PbO will be formed?

            A)  116 g    B)  46.6 g    C)  163 g    D)  69.9 g    E)  93.2 g

 

      71.  In the process of obtaining lead from PbS, or galena, the galena is “roasted” (heated in the presence of oxygen), so that the following reaction occurs:

            2PbS(s) + 3O₂(g) ® 2PbO(s)  + 2SO₂(g)

            If 35.2 g of PbS reacts with 15.5 g of oxygen, how many grams of PbO will be formed?

            A)  32.8 g    B)  72.1 g    C)  105 g    D)  65.7 g    E)  49.2 g

 

      72.  What mass (in grams) of SF₆ should be produced by the following reaction if 7.00 g of sulfur is mixed with 9.00 g of fluorine?

            S + 3F₂ ® SF₆

            A)  24.0    B)  6.40    C)  11.6    D)  32.0    E)  16.0

 

      73.  If the theoretical yield for a reaction is 54.9 g, and 51.3 g are actually obtained, the percent yield is:

            A)      0.934%                                                  D)      3.60%

            B)      93.4%                                                    E)      not enough information given

            C)      107%                                                              

 

      74.  If the theoretical yield for a reaction is 29.4 g, and 28.7 g are actually obtained, the percent yield is:

            A)      0.976%                                                  D)      0.700%

            B)      102%                                                     E)      not enough information given

            C)      97.6%                                                             

 

      75.  If the theoretical yield for a reaction is 72.3 g, and 65.2 g are actually obtained, the percent yield is:

            A)      90.2%                                                    D)      111%

            B)      0.902%                                                  E)      not enough information given

            C)      7.10%                                                             

 

      76.  Aluminum metal reacts with sulfuric acid according to the equation:

            2Al(s) + 3H₂SO₄(aq) ® Al₂(SO₄)₃(s) + 3H₂(g)

            If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al₂(SO₄)₃ are collected, what is the percent yield for the reaction?

            A)  63.4%    B)  85.5%    C)  117%    D)  47.1%    E)  not enough information given

 

      77.  Aluminum metal reacts with sulfuric acid according to the equation:

            2Al(s) + 3H₂SO₄(aq) ® Al₂(SO₄)₃(s) + 3H₂(g)

            If 12.9 g of aluminum reacts with excess sulfuric acid, and 62.4 g of Al₂(SO₄)₃ are collected, what is the percent yield for the reaction?

            A)  81.8%    B)  49.5%    C)  76.3%    D)  131%    E)  not enough information given

 

      78.  Iron metal reacts with hydrochloric acid as follows:

            2Fe(s) + 6HCl(aq) ® 2FeCl₃(aq) + 3H₂(g)

            If 22.4 g of iron react with excess HCl, and 59.4 g of FeCl₃ are collected, what is the percent yield of the reaction?

            A)  65.0%    B)  109%    C)  91.4%    D)  73.0%    E)  not enough information given

 

      79.  Iron metal reacts with hydrochloric acid as follows:

            2Fe(s)  + 6HCl(aq) ® 2FeCl₃(aq) + 3H₂(g)

            If 35.6 g of iron react with excess HCl, and 98.6 g of FeCl₃ are collected, what is the percent yield of the reaction?

            A)  103%    B)  104%    C)  95.7%    D)  63.0%    E)  not enough information given

 

      80.  Which of the following processes is exothermic?

            A)      ice melting in a beverage

            B)      dry ice (solid CO₂) converting to a gas at room temperature

            C)      evaporation of water from a mud puddle

            D)      burning propane in a barbeque grill

            E)      wax melting on the top of a burning candle

 

      81.  Which of the following is an exothermic process?

            A)      ice melting

            B)      water evaporating

            C)      boiling soup

            D)      condensation of water vapor

            E)      Ammonium thiocyanate and barium hydroxide are mixed, resulting in a decrease in temperature of the surroundings.

 

      82.  Which of the following processes is endothermic?

            A)      burning gasoline in an internal combustion engine

            B)      evaporation of perspiration on your skin

            C)      burning wood in a fireplace

            D)      condensing steam on a mirror

            E)      hot coffee cooling down as it sits on the table

 

      83.  Which of the following is an exothermic process?

            A)      ice melting

            B)      water evaporating

            C)      boiling soup

            D)      condensation of water vapor

            E)      Ammonium thiocyanate and barium hydroxide are mixed, resulting in a decrease in temperature.

 

      84.  Which of the following processes is exothermic?

            A)      boiling water to make tea

            B)      cooking an egg

            C)      heating food in a microwave oven

            D)      an acid and base reacting together, and causing the solution to become warm

            E)      water in a swimming pool getting warmer in the sun

 

      85.  The following reaction consumes 393 kJ of heat for each mole of CO₂ that reacts.

            CO₂(g)   ®  C(s) + O₂(g)

            This reaction

            A)      is endothermic.                                      D)      cannot possibly occur.

            B)      is exothermic.                                        E)      is a synthesis reaction.

            C)      has a negative q.                                             

 

      86.  A hot breeze may seem cool to a swimmer who has just come out of the water because

            A)      the evaporation of water from the swimmer's wet body absorbs heat.

            B)      water is a good conductor of heat.

            C)      water has a high specific heat.

            D)      water has a higher density than air.

            E)      condensation of moisture in the air releases heat.

 

      87.  Consider the following specific heats of metals.

            Metal         Specific Heat (J/g °C)

            copper          0.377

            calcium     0.656

            aluminum     0.895

            iron          0.448

            lead          0.129

            If the same amount of heat is added to 25.0 g of each of these metals, all at the same initial temperature, which metal will have the highest final temperature?

            A)  copper    B)  calcium    C)  aluminum    D)  iron    E)  lead

 

      88.  Consider the following specific heats of metals.

            Metal         Specific Heat (J/g °C)

            copper          0.377

            calcium     0.656

            aluminum     0.895

            iron          0.448

            lead          0.129

            If the same amount of heat is added to 50.0 g of each of these metals, all at the same initial temperature, which metal will have the lowest final temperature?

            A)  copper    B)  calcium    C)  aluminum    D)  iron    E)  lead

 

      89.  If 75.0 J of heat energy are added to separate 25.0 g samples of gold (C = 0.129 J/g^oC), silver (C = 0.234 J/g^oC), aluminum (C = 0.895 J/g^oC), chromium (C = 0.450 J/g^oC), and copper (C = 0.377 J/g^oC), rank the metals in order from least to greatest final temperature.

            A)      Au < Ag < Cu < Cr < Al

            B)      Al < Cr < Cu < Ag < Au

            C)      Au < Ag < Al < Cr < Cu

            D)      Cr < Cu < Al < Ag < Au

            E)      none of these—all final temperatures would be equal

 

      90.  If an equal quantity of heat is transferred to 10.0 g samples of liquid water (C = 4.184 J/g°C), concrete (C = 0.88 J/g°C), asphalt (C = 0.920 J/g°C), glass (C = 0.84 J/g°C), and iron (C = 0.448 J/g°C), rank the final temperatures of the samples from least to greatest.

            A)      iron < glass < concrete < asphalt < water

            B)      water < asphalt < concrete < glass < iron

            C)      asphalt < concrete < glass < iron < water

            D)      iron < concrete < glass < asphalt < water

            E)      water < concrete < asphalt < glass < iron

 

      91.  A carton of low-fat yogurt says it has 1.70 ´ 10² Calories.  What is the equivalent amount of energy in terms of joules?

            A)  711 J    B)  711,000 J    C)  40,600 J    D)  406 J    E)  40.6 J

 

      92.  A can of soda has 1.50 ´ 10² Calories.  Convert this energy to units of joules.

            A)  628 J    B)  6280 J    C)  35.9 J    D)  3.59 ´ 10⁴ J    E)  6.28 ´ 10⁵ J

 

      93.  A 43 g serving of a chocolate candy has 2.10 ´ 10² Calories.  Convert this energy to units of joules.

            A)  879 J    B)  8.79 ´ 10⁵ J    C)  50.2 J    D)  5.02 ´ 10⁴ J    E)  8.79 ´ 10³ J

 

      94.  When carbon dioxide is formed from its elements, 393.5 kJ of energy is released.  Convert this energy to units of calories.

            A)      9.405 ´ 10⁴ cal                                       D)      1.646 ´ 10³ cal

            B)      94.05 cal                                                E)      1.646 ´ 10⁶ cal

            C)      0.3935 cal                                                       

 

      95.  When sulfur dioxide is formed from its elements, 296.8 kJ of energy is released.  Convert this energy to units of calories.

            A)      70.94 cal                                                D)      1.242 ´ 10³ cal

            B)      7.094 ´ 10⁴ cal                                       E)      1.242 ´ 10⁶ cal

            C)      0.2968 cal                                                       

 

      96.  An energy input of 227 kJ is required to form acetylene from its elements.  Convert this energy to units of calories.

            A)      9.50 ´ 10² cal                                         D)      54.3 cal

            B)      9.50 ´ 10⁵ cal                                         E)      5.43 ´ 10⁴ cal

            C)      0.227 cal                                                         

 

      97.  Equal masses of ice at 0°C and water at 100°C are mixed in an insulated container.

            Estimate the final temperature of the mixture.

            A)      between 51 and 99°C                            D)      0°C

            B)      between 1 and 49°C                              E)      100°C

            C)      50°C                                                               

 

      98.  How much heat energy would be needed to raise the temperature of a 15.0 g sample of iron (C = 0.448 J/g°C) from 22.0°C to 100.0°C?

            A)      34.9 J                                                     D)      1.17 ´ 10³ J

            B)      672 J                                                      E)      not enough information given

            C)      524 J                                                               

 

      99.  How much heat energy would be needed to raise the temperature of a 22.3 g sample of aluminum (C = 0.895 J/g°C) from 22.5°C to 55.0°C?

            A)      20.0 J                                                     D)      8.10 ´ 10² J

            B)      649 J                                                      E)      not enough information given

            C)      725 J                                                               

 

    100.  How much heat energy would be needed to raise the temperature of a 32.0 g sample of gold (C = 0.129 J/g°C) from 21.8°C to 75.0°C?

            A)      3.10 ´ 10² J                                           D)      90.0 J

            B)      1.32 ´ 10⁴ J                                           E)      not enough information given

            C)      2.20 ´ 10² J                                                    

 

    101.  What is the heat change when a 53.5 g sample of water (C = 4.184 J/g°C) is cooled from 98.0°C to 23.2°C?

            A)      1.67 ´ 10⁴ J                                           D)      -956 J

            B)      -1.67 ´ 10⁴ J                                          E)      not enough information given

            C)      2.19 ´ 10⁴ J                                                    

 

    102.  What is the heat change when a 26.8 g sample of water (C = 4.184 J/g°C) is cooled from 75.6°C to 22.1°C?

            A)      6.00 ´ 10³ J                                           D)      -1.43 ´ 10³ J

            B)      -6.00 ´ 10³ J                                          E)      not enough information given

            C)      1.43 ´ 10³ J                                                    

 

    103.  What is the heat change when a 225 g sample of olive oil (C = 1.79 J/g C) is cooled from 95.8°C to 52.1°C?

            A)      9.83 ´ 10³ J                                           D)      1.76 ´ 10⁴ J

            B)      -9.83 ´ 10³ J                                          E)      not enough information given

            C)      -1.76 ´ 10⁴ J                                                   

 

    104.  A 5.00 g sample of a brownie with nuts is burned in a bomb calorimeter containing 2025 g of water.  The temperature of the water increases from 23.50°C to 33.47°C.  How much heat, in joules, did the brownie release when it burned?  (C_water = 4.184 J/g°C)

            A)      1.99 ´ 10⁵ J                                           D)      8.45 ´ 10⁴ J

            B)      2.80 ´ 10⁵ J                                           E)      7.00 ´ 10² J

            C)      4.92 ´ 10² J                                                    

 

    105.  A 2.50 g sample of pitted prunes is burned in a bomb calorimeter containing 2110 g of water.  The temperature of the water increases from 22.50°C to 25.76°C.  How much heat, in joules, did the prune sample release when it burned?  (C_water = 4.184 J/g°C)

            A)      1.99 ´ 10⁵ J                                           D)      2.35 ´ 10² J

            B)      2.27 ´ 10⁵ J                                           E)      2.69 ´ 10² J

            C)      2.88 ´ 10⁴ J                                                    

    106.  A 3.50 g sample of rice is burned in a bomb calorimeter containing 1980 g of water.  The temperature of the water increases from 22.75°C to 28.88°C.  How much heat, in joules, did the rice sample release when it burned?  (C_water = 4.184 J/g°C)

            A)      1.88 ´ 10⁵ J                                           D)      3.33 ´ 10² J

            B)      2.39 ´ 10⁵ J                                           E)      4.22 ´ 10² J

            C)      5.08 ´ 10⁴ J                                                    

 

    107.  Consider the reaction, CaCO₃(s) ® CaO(s) + CO₂(g)     q = 178.0 kJ

            How much heat would be required to decompose exactly 4 mol CaCO₃(s)?

            A)  1780 kJ    B)  712 kJ    C)  178 kJ    D)  44.5 kJ    E)  89.0 kJ

 

    108.  The coefficients of a balanced equation can be understood to represent either molecules or moles.

 

    109.  The coefficients of a balanced equation can be understood to represent either moles or mass.

 

    110.  The number of moles of reactant molecules must always equal the number of moles of  product molecules in a balanced equation.

 

    111.  The limiting reactant in a chemical reaction is always the reactant which is present in the least amount in terms of mass.

 

    112.  When calculating the percent yield of a reaction, the only information necessary is the mass of the starting materials.

 

    113.  A calorie used by nutritionists is equal to 1000 cal or 1 kcal used by chemists.

 

    114.  One calorie is the amount of heat energy required to raise the temperature of 10.0 g of water by 1^oC.

 

    115.  When a substance cools from a high temperature to a low temperature, its heat change will have a negative sign.

 

    116.  The heat capacity of a substance is the amount of heat energy that is needed to cause the substance to melt.

 

    117.  In a bomb calorimeter, the bomb itself, the water surrounding it, and the thermometer would be considered part of the “system.”

 

    118.  When fats or other foods are burned in a bomb calorimeter, the system absorbs heat, so the reaction is endothermic.

 

    119.  When blue copper(II) sulfate pentahydrate is heated, it decomposes according to the equation given below, forming light blue copper(II) sulfate and water vapor.

            CuSO₄?5H₂O(s) ® CuSO₄(s) + 5H₂O(g)

            If a 5.00 g sample of CuSO₄?5H₂O is heated, how many g of CuSO₄ will be formed when the reaction is complete?

 

    120.  When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the equation:

            4K(s) + O₂(g)® 2K₂O(s)

            If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of oxygen reacted with the potassium?

 

    121.  When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the equation:

            4K(s) + O₂(g)® 2K₂O(s)

            If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of potassium reacted?

 

    122.  When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the equation:

            4K(s) + O₂(g)® 2K₂O(s)

            If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of K₂O formed?

 

    123.  Given the unbalanced equation:

            Cr(s) + Cl₂(g) ® CrCl₃(s)

            Balance the equation, and determine how many grams of chromium would be required to react completely with 4.50 g of chlorine.

 

    124.  Given the equation for the combustion of octane:

            2C₈H₁₈(l) + 25O₂(g) ® 16CO₂(g) + 18H₂O(g)

            If 50.0 g of each reactant are available, how much CO₂ will be formed?

 

    125.  An aqueous solution containing 15.0 g of NaOH is mixed with an aqueous solution containing 15.0 g of H₂SO₄. Write a balanced equation for the reaction that will occur.

    126.  An aqueous solution containing 15.0 g of NaOH is mixed with an aqueous solution containing 15.0 g of H₂SO₄. Identify the limiting reactant.

 

    127.  An aqueous solution containing 15.0 g of NaOH is mixed with an aqueous solution containing 15.0 g of H₂SO₄. Will the solution be acidic or basic when the reaction is complete?

 

    128.  In photosynthesis, plants convert carbon dioxide and water into glucose, C₆H₁₂O₆, according to the reaction:

            6CO₂(g) + 6H₂O(l) ® 6O₂(g) + C₆H₁₂O₆(g)

            How many grams of glucose can be synthesized from 117 g of CO₂, assuming there is sufficient water to react with all of the CO₂?

 

    129.  In photosynthesis, plants convert carbon dioxide and water into glucose, C₆H₁₂O₆, according to the reaction:

            6CO₂(g) + 6H₂O(l) ® 6O₂(g) + C₆H₁₂O₆(g)

             If 75.2 g of glucose are obtained, what is the percent yield of the reaction?

 

    130.  The combustion of 16.0 g of methane gas produces 8.90 ´ 10² kJ of energy.  Convert this energy to units of calories.

 

    131.  How much heat must be added to 125 g of copper (C = 0.377 J/g° C) at 25.0°C to raise its temperature to 78.4°C?

 

    132.  The heat change that accompanies the formation of 1.00 mole of CO from its elements is -110.5 kJ/mol.  What heat change would occur if 2.35 mol of CO were formed?

 

    133.  The burning of a 2.50 g sample of cheese pizza in a bomb calorimeter gives off 2.53 ´ 10⁴ J of energy.  If the calorimeter contains 2350 g of water, what was the temperature change of the water?  (C_water = 4.184 J/g° C)