This Document Contains Chapters 7 to 8 Chapter 7 Chemical Reactions True/False Questions 1. The reaction of baking soda and vinegar to produce carbon dioxide gas is an example of a precipitation reaction. Answer: False 2. The reaction of carbonate ion with magnesium ion to form solid magnesium carbonate is an example of an oxidation reduction reaction. Answer: False 3. Combustion reactions are a subcategory of oxidation-reduction reactions. Answer: True 4. Color change is evidence that a chemical reaction has occurred. Answer: True 5. The formation of a gas is evidence of a chemical reaction while the emission of light is not. Answer: False 6. The formation of either a solid or a gas is evidence of a chemical reaction. Answer: True 7. Bubbles in water that appear during boiling show that a chemical reaction is occurring. Answer: False 8. When balancing a chemical equation you may alter the coefficients but not the subscripts in the equation. Answer: True 9. The following equation IS balanced: CH4 + 2O2 → CO2 + H2O Answer: False 10. The following reaction IS balanced: BaCl2 + H2SO4 → 2HCl + BaSO4 Answer: True 11. The following equation is balanced: 2 C4H10O + 13 O2 → 8 CO2 + 10 H2O Answer: False 12. The following reaction IS balanced: AgNO3 + 2NH4Cl → AgCl + (NH4)2NO3 Answer: False 13. The following equation IS balanced: HNO3 + NaHSO3 → NaNO3 + H2O + SO2 Answer: True 14. A strong electrolyte solution contains ionic compounds that completely dissociate in water. Answer: True 15. An insoluble compound will partially dissolve in water. Answer: False 16. When compounds containing polyatomic ions dissolve, the polyatomic ions usually dissolve as intact units. Answer: True 17. Li+, Na+, K+ and NH4+ compounds are soluble. Answer: True 18. Cl-, Br-, and I- are mostly insoluble. Answer: False 19. Mixing two aqueous solutions will always result in formation of a precipitate. Answer: False 20. A precipitation reaction occurs when water is formed as a product. Answer: False 21. The key to predicting a precipitation reaction is the formation of an insoluble compound from soluble compounds. Answer: True 22. A precipitation reaction will occur when sodium chloride is mixed with potassium nitrate. Answer: False 23. A precipitate will form when you mix solutions of potassium chloride and lead nitrate. Answer: True 24. We remove the spectator ions from the complete ionic equation to form the net ionic equation. Answer: True 25. A net ionic equation shows all ionic species that are present in solution. Answer: False 26. A spectator ion is one that does not actively participate in a chemical reaction. Answer: True 27. Mixing HNO3 (aq) and NaHCO3 (aq) will produce carbon dioxide gas as a product. Answer: True 28. One of the characteristics of an acid-base reaction is that this type of reaction forms water. Answer: True 29. An acid-base reaction always produces a salt plus carbon dioxide. Answer: False 30. Carbon dioxide gas is a product when an acid reacts with a carbonate or a bicarbonate. Answer: True 31. The net ionic equation for the reaction of sodium hydroxide plus hydrochloric acid is Na+ + Cl- → NaCl. Answer: False 32. An oxidation-reduction reaction must involve reaction with oxygen. Answer: False 33. Evidence of a redox reaction is when a substance reacts with elemental oxygen. Answer: True 34. Evidence of a redox reaction is when one substance transfers protons to another substance. Answer: False 35. In an oxidation-reduction reaction, if one substance loses electrons, then another substance must gain electrons. Answer: True 36. Combustion reactions emit heat and so can be classified as endothermic. Answer: False 37. Decomposition reactions usually require energy to initiate the reaction. Answer: True Multiple Choice Questions 38. A reaction which forms a gaseous product is an example of a(n) __________. A) oxidation-reduction reaction B) combustion reaction C) precipitation reaction D) gas evolution reaction E) none of the above Answer: D 39. A reaction which forms a solid product is an example of a(n) __________. A) oxidation-reduction reaction B) combustion reaction C) precipitation reaction D) gas evolution reaction E) none of the above Answer: C 40. A reaction in which a substance reacts with oxygen, emitting heat and forming oxygen-containing compounds is an example of a(n) A) acid-base reaction. B) combustion reaction. C) precipitation reaction. D) gas evolution reaction. E) none of the above Answer: B 41. Which of the following is NOT evidence that a chemical reaction has occurred? A) color change when chemicals are contacted with each other B) solid formation when chemicals are contacted with each other C) gas formation when chemicals are contacted with each other D) emission of light when chemicals are contact with each other E) All of the above are evidence of a chemical reaction. Answer: E 42. Which of the following is NOT a sign of a chemical reaction? A) absorbing heat when chemicals are contacted with each other B) emission of heat when chemicals are contacted with each other C) emission of light when chemicals are contacted with each other D) absorbing light when chemicals are contacted with each other E) All of the above are signs of a chemical reaction. Answer: D 43. When water is heated, bubbles form in the water. Is this evidence of a chemical reaction? Why? A) No, boiling water is a physical change. B) Yes, the formation of a gas is evidence of a chemical reaction. C) No, the formation of gas bubbles is a secondary chemical reaction which is ignored. D) Yes, the formation of a gas is proof a new compound has been made. E) none of the above Answer: A 44. Which of the following statements about balancing reactions is FALSE? A) If there is no coefficient or subscript, a one is implied. B) When coefficients are added the type of compounds is changed in the chemical reaction. C) Subscripts are multiplied by the coefficients to determine the number of atoms in a compound. D) Coefficients are added to compounds to ensure both sides of the reaction have equal numbers of each atom. E) All of the above statements are true. Answer: B 45. Before a chemical equation can be written, one must know A) the atomic mass of all the elements involved. B) the molar mass of all the compounds. C) the symbols and formulas of all reactants and products. D) the number of moles of all reactants and products. E) none of the above. Answer: C 46. When the equation, ___N2 + ___H2 → ___NH3 is balanced, the coefficient of hydrogen is: A) 1 B) 2 C) 3 D) 4 E) none of the above Answer: C 47. When the equation, ___O2 + ___C5H12 → ___CO2 + ___H2O is balanced, the coefficient: of O2 is: A) 3 B) 4 C) 5 D) 8 E) none of the above Answer: D 48. What are the coefficients for the following reaction when it is properly balanced? ___HCl + ___Mg → ___MgCl2 + ___ H2 A) 2, 1, 1, 1 B) 2, 1, 2, 2 C) 1, 2, 1/2, 1 D) 1, 1, 1, 2 E) none of the above Answer: A 49. What are the coefficients for the following reaction when it is properly balanced? ___O2 + ___CH4 → ___CO2 + ___H2O A) 2, 1, 3, 1 B) 2, 3, 2, 2 C) 1, 3, 2, 1 D) 2, 1, 1, 2 E) none of the above Answer: D 50. What are the coefficients for the following reaction when it is properly balanced? ___Na3PO4 + ___Ba(NO3)2 → ___NaNO3 + ___Ba3(PO4)2 A) 2, 1, 1, 3 B) 2, 3, 1, 6 C) 2, 3, 6, 1 D) 6, 1, 3, 2 E) none of the above Answer: C 51. What are the coefficients for the following reaction when it is properly balanced? ___nitric acid + ___sodium hydroxide → ___sodium nitrate + ___water A) 2, 1, 1, 1 B) 2, 3, 2, 2 C) 5, 2, 2, 1 D) 1, 1, 1, 1 E) none of the above Answer: D 52. What are the coefficients for the following reaction when it is properly balanced? ___potassium iodide + ___lead (II) acetate → ___lead (II) iodide +___potassium acetate A) 2, 1, 1, 1 B) 2, 1, 1, 2 C) 3, 2, 2, 1 D) 1, 1, 2, 2 E) none of the above Answer: B 53. What are the coefficients for the following reaction when it is properly balanced? ___nitrogen monoxide + ___carbon monoxide → ___nitrogen +___carbon dioxide A) 2, 1, 1, 2 B) 2, 2, 1, 2 C) 2, 2, 2, 1 D) 1, 1, 2, 2 E) none of the above Answer: B 54. When the equation __Ca3N2 + __H2O → __Ca(OH)2 + __NH3 is balanced, the coefficient of H2O is: A) 2 B) 3 C) 6 D) 12 E) none of the above Answer: C 55. When the equation __NO2 + __H2O + __O2 → __HNO3 is balanced, the coefficient of HNO3 is A) 2. B) 3. C) 4. D) 5. E) none of the above Answer: C 56. Which of the following equations is NOT balanced properly? A) 2Cr + 6HCl → 2CrCl3 + 3H2 B) 2NaHCO3 → Na2CO3 + CO2 + H2O C) Cr2(SO4)3 + 6KOH → 2Cr(OH)3 + 3 K2SO4 D) 4NH3 + 14O2 → 4NO2 + 6H2O E) none of the above Answer: D 57. Sodium metal reacts with water to form aqueous sodium hydroxide and hydrogen gas. Which equation below best describes the balanced equation for this reaction? A) Na + H2O → NaOH (aq) + H (g) B) S + H2O → SOH (aq) + H (g) C) Na + H2O → NaOH (aq) + H2 (g) D) 2Na + 2H2O → 2NaOH (aq) + H2 (g) E) 2Na + H2O → Na2OH (aq) + H (g) Answer: D 58. An aqueous solution is: A) any liquid with another compound dissolved in it. B) an ionic compound with water dissolved in it. C) water with a molecular compound dissolved in it. D) water with another compound dissolved in it. E) none of the above Answer: D 59. Which of the following compounds is INSOLUBLE? A) potassium acetate B) lithium carbonate C) magnesium bromide D) aluminum sulfide E) none of the above Answer: D 60. Which of the following compounds is INSOLUBLE? A) magnesium phosphate B) magnesium sulfate C) magnesium iodide D) magnesium nitrate E) none of the above Answer: A 61. Which of the following compounds is SOLUBLE? A) copper carbonate B) calcium carbonate C) potassium carbonate D) strontium carbonate E) none of the above Answer: C 62. Which of the following compounds is SOLUBLE? A) aluminum hydroxide B) aluminum sulfide C) aluminum carbonate D) aluminum sulfate E) none of the above Answer: D 63. All of the following compounds are soluble in water EXCEPT A) NaCl. B) CaCl2. C) FeCl3. D) NH4Cl. E) PbCl2. Answer: E 64. The compound sodium sulfate is soluble in water. When this compound dissolves in water, which ion listed below would be present in solution? A) SO42- B) S2- C) O2- D) Na22+ E) none of the above Answer: A 65. When solid NaCl is stirred into water, which of the following is NOT true? A) Individual sodium and chloride ions are present. B) The solution will conduct electricity. C) The solution will taste salty. D) The NaCl will fail to dissociate. E) none of the above Answer: D 66. If you had an aqueous mixture that contained Ag+, K+, and Pb+2 cations, how many different solids could precipitate if a chloride solution was added? A) 1 B) 2 C) 3 D) 4 E) no solids will precipitate Answer: B 67. In writing the chemical equation for a precipitation reaction, what abbreviation of the physical state must appear with one of the products? A) (s) B) (g) C) (l) D) (w) E) none of the above Answer: A 68. What type of a reaction occurs when a potassium nitrate solution is mixed with a barium acetate solution? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction Answer: E 69. A precipitate is expected to be formed when an aqueous solution of sodium sulfate is added to an aqueous solution of A) iron(III) chloride. B) potassium chloride. C) magnesium chloride. D) barium chloride. E) none of the above Answer: D 70. What would be the formula of the precipitate that forms when Pb(NO3)2 (aq) and K2SO4 (aq) are mixed? A) K(NO3)2 B) PbSO4 C) PbK2 D) H2O E) none of the above Answer: B 71. Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which compound would not form ions in the complete ionic equation? A) PbI2 B) KNO3 C) Pb(NO3)2 D) KI E) All compounds form ions in the complete ionic equation. Answer: A 72. Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which ion would NOT be present in the complete ionic equation? A) Pb2+ B) K+ C) NO3- D) I- E) All the above ions are in the complete ionic equation. Answer: E 73. Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which ion(s) would NOT be present in the net ionic equation? A) Pb2+, NO3- B) K+, NO3- C) K+, Pb2+ D) K+, I- E) All the above ions are in the net ionic equation. Answer: B 74. Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which ion(s) would NOT be spectator ions? A) Pb2+, NO3- B) K+, I- C) NO3-, Pb2+ D) Pb2+, I - E) All the above ions are in the net ionic equation. Answer: D 75. Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) What is the correct complete ionic equation? A) Pb2+ + (NO3)2- + 2K+ + 2I- → PbI2(s) + 2K+ + 2NO3- B) Pb2+ + 2NO3- +2K+ + I- → PbI2(s) + 2K+ + NO3- C) Pb2+ + 2NO3- + 2K+ + 2I- → PbI2(s) + 2K+ + 2NO3- D) Pb2+ + 2NO3- + 2K+ + 2I- → Pb2+ + 2I- + 2K+ + 2NO3- E) none of the above Answer: C 76. Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) What is the correct net ionic equation? A) Pb2+ + I2- → PbI2(s) B) 2NO3- + 2K+ → 2KNO3 C) Pb2+ + 2NO3- + 2K+ + 2I- → PbI2(s) + 2K+ + 2NO3- D) Pb2+ + 2I- → PbI2(s) E) none of the above Answer: D 77. Which of the following statements about writing molecular, complete and net ionic equations is FALSE? A) A molecular equation is a chemical equation showing the complete, neutral formulas for every compound in a reaction. B) A complete ionic equation is a chemical equation showing all of the species as they are actually present in solution. C) A net ionic equation is an equation showing only the species that actually change during the reaction. D) A spectator ion remains unchanged in the reaction and appears on both sides of the equation. E) All of the statements are true. Answer: E 78. Which is a spectator ion from the following complete ionic equation: Ag+(aq) + NO3-(aq) + K+ (aq) + Br-(aq) → AgBr(s) + K+(aq) + NO3- (aq) A) Ag+ B) Br- C) K+ D) AgBr E) none of the above Answer: C 79. Which of the following everyday substances does NOT typically contain an acid? A) lemons B) vinegar C) soap D) limes E) all of the above Answer: C 80. What type of a reaction occurs when a silver nitrate solution is mixed with sodium chloride solution? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction Answer: A 81. What type of a reaction occurs when a sodium hydroxide solution is mixed with an acetic acid solution? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction Answer: B 82. What is the net ionic equation for the reaction of hydrochloric acid with potassium hydroxide? A) H+ + Cl- + K+ + OH- → H2O + K+ + Cl- B) HCl + KOH → H2O + KCl C) H+ + OH- → H2O D) 2H+ +2Cl- + K2+ + 2OH- → H2O + K2+ +2 Cl- E) none of the above Answer: C 83. What is the molecular equation for the reaction of hydrochloric acid with potassium hydroxide? A) H2Cl + 2KOH → H2O +2KCl B) 2HCl + K(OH)2 → 2H2O + KCl2 C) H+ + OH- → H2O D) HCl + KOH → H2O + KCl E) none of the above Answer: D 84. What is the complete ionic equation for the reaction of hydrochloric acid with potassium hydroxide? A) H+ + Cl- + K+ + OH- → H2O + K+ + Cl- B) H+ + Cl- + K+ + OH- → 2H+ + O2- + K+ + Cl- C) H+ + OH- → H2O D) 2H+ +2Cl- + K2+ + 2OH- → H2O + K2+ +2 Cl- E) none of the above Answer: A 85. When a solution of MgCl2 and one of AgNO3 are mixed, the net ionic equation is: A) Mg2+(aq) + 2Cl-(aq) + 2Ag+(aq) + 2NO3- (aq) → Mg2+(aq) + 2NO3-aq) + 2AgCl(s) B) Mg2+(aq) + 2Cl-(aq) + 2Ag+(aq) + 2NO3- (aq) → Mg(NO3)2 (aq) + 2 AgCl(s) C) Mg2+(aq) + 2NO3-(aq) → Mg(NO3)2(aq) D) Cl-(aq) + Ag+(aq) → AgCl(s) E) none of the above Answer: D 86. Which of the following types of compounds will NOT undergo a gas evolution reaction when acid is added? A) sulfides B) carbonates C) hydroxides D) bisulfites E) none of the above Answer: C 87. What is the gas produced when hydrochloric acid is reacted with ammonium carbonate? A) ammonia B) chlorine C) hydrogen D) carbon dioxide E) none of the above Answer: D 88. What type of a reaction occurs when a hydrochloric acid solution is mixed with a sodium bicarbonate solution? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction Answer: D 89. Which of the following would NOT be a product from mixing hydrochloric acid with a solution of sodium sulfite? A) H2O (l) B) SO2 (g) C) NaCl (aq) D) H2 (g) E) none of the above Answer: D 90. What type of a reaction occurs when potassium metal reacts with fluorine gas? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction Answer: C 91. Identify the oxidation-reduction reactions among the following: 1. Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s) 2. 2 Na(s) + Cl2(aq) → 2NaCl(s) 3. 2 Mg(s) + O2(g) → 2 MgO A) 1 and 2 only B) 1 and 3 only C) 2 and 3 only D) All of 1, 2, and 3 E) None of 1, 2, and 3 Answer: D 92. Methane gas (CH4), on complete combustion in air, produces: 1. CO2 2. H2 3. H2O A) 1 and 2 only B) 1 and 3 only C) 2 and 3 only D) All of 1 and 2 only E) None of Answer: B 93. A redox reaction has occurred ________. A) when a substance reacts with elemental oxygen B) when an alkali metal reacts with an alkaline earth metal C) when one substance transfers protons to another D) when one substance forms a solid E) when all of the above occur Answer: A 94. Which of the following statements about redox reactions is FALSE? A) Oxidation is the loss of electrons. B) Reduction is the gain of electrons. C) A reaction can result in either oxidation or reduction, not both. D) A reaction involving elemental oxygen is a redox reaction. E) All of the above statement are true. Answer: C 95. The reaction CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g) is A) a combustion reaction. B) a redox reaction. C) an exothermic reaction. D) all of the above E) none of the above Answer: D 96. What type of reaction is the generic equation A + B → AB? A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above Answer: A 97. What type of reaction is the generic equation A + BC → AC + B? A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above Answer: C 98. What type of reaction is the generic equation AB + CD → AD + CB? A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above Answer: D 99. What type of reaction is the generic equation AB → A + B? A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above Answer: B 100. What must be supplied for most decomposition reactions to happen? A) energy B) heat C) electrical current D) light E) any of the above Answer: E 101. Identify the double displacement reactions among the following: 1. KCl(aq) + AgNO3(aq) → AgCl(s) + KNO3(aq) 2. Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq) 3. H2SO4((aq) + 2NaOH(aq) → Na2SO4((aq) + 2H2O(l) A) 1 and 2 only B) 1 and 3 only C) 2 and 3 only D) All of 1, 2, and 3 E) None of 1, 2, and 3 Answer: D 102. Which statement about ozone is TRUE? A) Ozone normally forms in the upper atmosphere. B) Chlorofluorocarbons deplete the ozone layer. C) Ozone protects life on Earth from harmful ultraviolet light. D) None of the above statements are true. E) All the of the first three statements are true. Answer: E Chapter 8 Quantities in Chemical Reactions True/False Questions 1. Greenhouse gases affect the temperature of the earth by blocking sunlight from reaching earth. Answer: False 2. Global warming is due to the greenhouse gases preventing heat from Earth escaping into space. Answer: True 3. The primary greenhouse gas is carbon dioxide. Answer: True 4. The primary source for the rising carbon dioxide levels is respiration of the Earth's growing population. Answer: False 5. One of the advantages of burning fossil fuels is that it produces O2 for humans to breathe. Answer: False 6. Stoichiometry is a chemist's version of following a recipe. Answer: True 7. Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins. You can make 9 muffins from 3.5 cups of flour. Answer: False 8. Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins. You can make 1 dozen muffins from 3 eggs. Answer: True 9. If it takes 2 cups of milk and 1 cup of cocoa mix to make three servings of hot chocolate, and you only have 1 cup of each, then you cannot make any hot chocolate. Answer: False 10. Given the reaction: 2 Na(s) + Cl2(g) → 2 NaCl(s) The conversion factor for chlorine gas to sodium metal is: 2 mol Cl≡2 mol Na Answer: False 11. Given the reaction: 2 Na(s) + Cl2(g) → 2 NaCl(s) The conversion factor for chlorine gas to sodium chloride is: 1 mol Cl2≡2 mol NaCl Answer: True 12. Given the chemical equation: 2 Ca + O2 → 2 CaO, if 2 moles of CaO are formed in this reaction, then 2 moles of O2 must have reacted. Answer: False 13. Before determining conversion factors, it is necessary to make sure the equation is properly balanced. Answer: True 14. The conversion factor between mass and moles for a compound is the molar mass. Answer: True 15. The conversion factor for moles of carbon dioxide to mass of carbon dioxide is: 1 mole CO2≡44.01 g Answer: True 16. The limiting reactant is the reactant that produces the maximum amount of product. Answer: False 17. The theoretical yield is the amount of each reactant needed in order to make the maximum amount of product. Answer: False 18. The limiting reactant is the product that is completely consumed in a chemical reaction. Answer: False 19. The actual yield is the amount of product actually produced by a chemical reaction. Answer: True 20. The percent yield is calculated by dividing the actual yield by the theoretical yield times 100. Answer: True 21. Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins If you have 5 cups of flour, 3 eggs and plenty of blueberries, the limiting reactant is the eggs. Answer: False 22. Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins If you have 9 cups of flour, 4 eggs and plenty of blueberries, the theoretical yield of muffins is 16. Answer: True 23. The actual yield is the same as the theoretical yield if the reaction goes to completion and there is no loss of product. Answer: True 24. The limiting reactant determines what the actual yield is. Answer: False 25. The limiting reactant is not necessarily the reactant with the least mass. Answer: True 26. When viewing a chemical equation, the limiting reactant can never be a chemical on the product side of the equation. Answer: True 27. The percent yield can never be greater than 100%. Answer: True 28. For the following reaction you have 8 grams of hydrogen and 2 grams of oxygen. 2H2 + O2 → 2H2O The limiting reagent is the oxygen. Answer: True 29. For the following reaction you have 8 grams of hydrogen and 2 grams of oxygen. 2H2 + O2 → 2H2O The theoretical yield of the reaction is 4 grams of water. Answer: False 30. For the following reaction you have 8 grams of hydrogen and 2 grams of oxygen. 2H2 + O2 → 2H2O The excess reactant is the oxygen. Answer: False 31. If the theoretical yield of a reaction is 144 grams and the actual yield of the reaction is 72 grams, the percent yield of the reaction is 200%. Answer: False 32. The enthalpy of reaction, △H rxn, is the amount of thermal energy that flows when a reaction occurs at constant temperature. Answer: False 33. Thermal energy flows into the reaction and out of the surroundings in an endothermic reaction. Answer: True 34. An exothermic reaction has a negative enthalpy of reaction. Answer: True 35. Given the following generic equation, 2 A + 3B → A2B3 △H rxn = +444 kJ, if you completely reacted 1 mole of compound A, the amount of heat absorbed would be 222 kJ. Answer: True Multiple Choice Questions 34. The average global temperature depends on all factors EXCEPT what? A) the amount of incoming sunlight B) the amount of outgoing heat lost to space C) the amount of greenhouse gases D) the angle of the earth's surface in relation to the incoming sunlight E) All of the above are factors. Answer: D 35. Which of the below statements about global warming is FALSE? A) Some greenhouses gases are needed to keep the proper temperature balance. B) Greenhouse gases prevent heat from leaving the earth. C) Greenhouse gases allow sunlight to reach and heat the earth. D) If the level of greenhouse gases increases, the temperature will decrease. E) none of the above Answer: D 36. The primary cause of increasing greenhouse gases is: A) the burning of vast amounts of rain forests. B) the production of CO2 by respiration. C) the increased use of natural gas, petroleum and coal. D) the release of CO2 by decreasing solubility in the ocean. E) none of the above Answer: C 37. Which of the following is TRUE? A) Stoichiometry shows the numerical relationship between chemical quantities in a balanced chemical equation. B) Stoichiometry allows prediction of the amounts of products that form in a chemical reaction based on the amounts of reactants. C) Stoichiometry allows prediction of how much of the reactants are necessary to form a given amount of product. D) All of the above are true. E) None of the above are true. Answer: D 38. How many waffles can be made from 1 dozen eggs, assuming you have enough of all other ingredients? Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles A) 48 B) 12 C) 4 D) 16 E) not enough information Answer: D 39. How many eggs are needed to make 1 dozen waffles, assuming you have enough of all other ingredients? Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles A) 48 B) 9 C) 12 D) 16 E) not enough information Answer: B 40. How many moles of water are made from complete reaction of 2.2 moles of oxygen gas with hydrogen gas? Given the reaction: 2H2 + O2 → 2H2O A) 4.4 B) 1.1 C) 2.2 D) 3.3 E) not enough information Answer: A 41. How many moles of water are made from complete reaction of 1.4 moles of hydrogen gas? Given the reaction: 2H2 + O2 → 2H2O A) 2.8 B) 0.7 C) 1.4 D) 2.1 E) not enough information Answer: C 42. How many moles of H2 can be made from complete reaction of 3.0 moles of Al? Given: 2 Al + 6 HCl → 2 AlCl3 + 3 H2 A) 3 moles B) 3.0 moles C) 4.5 moles D) 9.0 moles E) none of the above Answer: C 43. How many moles of aluminum are needed to make 9 moles of molecular hydrogen? Given the reaction: 2 Al + 6 HCl → 2 AlCl3 + 3H2 A) 2 moles B) 3 moles C) 4 moles D) 6 moles E) none of the above Answer: D 44. How many moles of chlorine gas are needed to make 0.6 moles of sodium chloride? Given the reaction: 2Na + Cl2 → 2NaCl A) 0.6 B) 0.3 C) 1.2 D) 3.6 E) not enough information Answer: B 45. How many moles of sodium metal are needed to make 3.6 moles of sodium chloride? Given the reaction: 2Na + Cl2 → 2NaCl A) 0.9 B) 7.2 C) 1.8 D) 3.6 E) not enough information Answer: D 46. Suppose two chemical reactions are linked together in a way that the O2 produced in the first reaction goes on to react completely with Mg to form MgO in the second reaction. Reaction one: 2 KClO3 → 3 O2 + 2 KCl Reaction two: 2 Mg + O2 → 2 MgO If you start with 4 moles of KClO3, how many moles of MgO could eventually form? A) 2 moles B) 4 moles C) 6 moles D) 12 moles E) none of the above Answer: D 47. Given the balanced equation CH4 + 2 O2 → CO2 + 2 H2O, which of the following is NOT a correct conversion factor? A) 2 mole H2O = 18.02 g B) 1 mole O2 = 32.00 g C) 1 mole CH4 ≡ 2 mole H2O D) 2 mole O2 ≡ 1 mole CO2 E) none of the above Answer: A 48. How many grams of water are made from the reaction of 4.0 grams of hydrogen gas? Given the reaction: 2H2 + O2 → 2H2O A) 18 B) 72 C) 36 D) 4.5 E) not enough information Answer: C 49. How many grams of water are made from the reaction of 16.0 grams of oxygen gas? Given the reaction: 2H2 + O2 → 2H2O A) 18 B) 9 C) 36 D) 16 E) not enough information Answer: A 50. How many grams of chlorine gas are needed to make 117 grams of sodium chloride? Given the reaction: 2Na + Cl2 → 2NaCl A) 71.0 B) 142 C) 35.5 D) 48.2 E) not enough information Answer: A 51. How many grams of sodium metal are needed to make 29.3 grams of sodium chloride? Given the reaction: 2Na + Cl2 → 2NaCl A) 46.0 B) 5.75 C) 23.0 D) 11.5 E) not enough information Answer: D 52. Given that 4 NH3 + 5 O2 → 4 NO + 6 H2O, when 4.50 mol of H2O are formed, the amount of NO formed is A) 1.50 mol. B) 3.00 mol. C) 4.50 mol. D) 6.75 mol. E) none of the above Answer: B 53. Given that 4 NH3 + 5 O2 → 4 NO + 6 H2O, if 3.00 mol NH3 were made to react with excess of oxygen gas, the amount of H2O formed would be A) 2.00 mol. B) 3.00 mol. C) 4.50 mol. D) 6.00 mol. E) none of the above Answer: C 54. Iron metal reacts with oxygen to produce iron(III) oxide. If you have 12.0 moles of iron for complete reaction, you need A) 9.0 moles of O2 and produce 3.0 moles of Fe2O3. B) 12.0 moles of O2 and produce 24.0 moles of Fe2O3. C) 9.0 moles of O2 and produce 6.0 moles of Fe2O3. D) 4.5 moles of O2 and produce 3.0 moles of Fe2O3. E) none of the above Answer: C 55. Many metals react with halogens to give metal halides. For example, 2 Al (s) + 3 Cl2(g) → 2 AlCl3 (s) If you begin with 13.5 g of aluminum, A) you will need 23.6 g Cl2 for complete reaction and will produce 66.7 g of AlCl3. B) you will need 53.2 g Cl2 for complete reaction and will produce 66.7 g of AlCl3. C) you will need 26.6 g Cl2 for complete reaction and will produce 49.0 g of AlCl3. D) you will need 11.8 g Cl2 for complete reaction and will produce 49.0 g of AlCl3. E) none of the above Answer: B 56. A chemist wishes to perform the following reaction: N2 + 3 H2 → 2 NH3 If only 14.0 g of N2 is available, what is the minimum amount, in grams, of H2 needed to completely react with this quantity of N2? A) 1.01 g B) 1.51 g C) 3.03 g D) 6.06 g E) none of the above Answer: C 57. Which of the following statements is FALSE? A) The limiting reactant is completely consumed in a chemical reaction. B) The theoretical yield is the amount of product that can be made based on the amount of limiting reagent. C) The actual yield is the amount of product actually produced by a chemical reaction. D) The percent yield = Actual Yield/Theoretical Yield × 100% E) All of the above are true statements. Answer: E 58. Which ingredient is the limiting reactant if you have 5 cups of flour, 9 eggs and 3 tbs of oil? Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles A) flour B) eggs C) oil D) waffles E) not enough information Answer: A 59. What is the theoretical yield of waffles if you have 5 cups of flour, 9 eggs and 3 tbs of oil? Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles A) 10 B) 12 C) 6 D) 4 E) not enough information Answer: A 60. Which ingredient is the limiting reactant if you have 6 cups of flour, 9 eggs and 2 tbs of oil? Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles A) flour B) eggs C) oil D) waffles E) not enough information Answer: C 61. A tricycle factory uses the following items to produce one tricycle: 3 tires, 1 frame, and 2 pedals. If the factory has available 270 tires, 90 frames, and 170 pedals, which item would limit the amount of complete tricycles that can be assembled. A) tires B) frames C) pedals D) both tires and frames are limiting E) not enough information Answer: C 62. What is the theoretical yield of waffles if you have 6 cups of flour, 9 eggs and 2 tbs of oil? Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles A) 10 B) 12 C) 8 D) 4 E) not enough information Answer: C 63. Consider the following generic chemical equation: 2A + 5B → C + 3D If you react 4 units of A with 10 units of B, which statement is TRUE? A) Substance A will be the limiting reactant. B) Substance B will be the limiting reactant. C) There is just enough of A and B so that everything reacts completely. D) Substance C cannot be formed from this reaction. E) none of the above Answer: C 64. Consider the following generic chemical equation: 2W + 3X → 3Y + Z When 5 units of W and 6 units of X are allowed to react, the limiting reactant would be: A) W B) X C) Y D) Z E) There is no limiting reactant in this situation. Answer: B 65. Determine the theoretical yield of C when 3 units of A and 10 units of B are reacted in the following generic chemical equation: 2A + 5B → 4C. A) 3 B) 4 C) 6 D) 8 E) none of the above Answer: C 66. Given the balanced equation CO2 + Si → SiO2 + C, if you were to react 1 mole of CO2 with 1 mole of Si, which statement is TRUE? A) The CO2 is the limiting reactant. B) The Si is the limiting reactant. C) The SiO2 is the limiting reactant. D) You have equal stoichiometric amounts of reactants. E) none of the above Answer: D 67. If the theoretical yield of a reaction is 42.0 grams of product and the percent yield is 75%. How many grams were actually produced? A) 5400 B) 56 C) 32 D) 1.8 E) none of the above Answer: C 68. The theoretical yield of a reaction is 75.0 grams of product and the actual yield is 42.0g. What is the percent yield? A) 75.0 B) 56.0 C) 31.5 D) 178 E) none of the above Answer: B 69. What is the theoretical yield of a reaction if 25.0 grams of product were actually produced from a reaction that has a 88% yield? A) 28.4 B) 22.0 C) 3.52 D) 352 E) none of the above Answer: A 70. What is the limiting reactant for the following reaction given we have 3.4 moles of Ca(NO3)2 and 2.4 moles of Li3PO4? Reaction: 3Ca(NO3)2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4)2 A) Ca(NO3)2 B) Li3PO4 C) LiNO3 D) Ca3(PO4)2 E) not enough information Answer: A 71. What is the excess reactant for the following reaction given we have 3.4 moles of Ca(NO3)2 and 2.4 moles of Li3PO4? Reaction: 3Ca(NO3)2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4)2 A) Ca(NO3)2 B) Li3PO4 C) LiNO3 D) Ca3(PO4)2 E) not enough information Answer: B 72. How many moles of lithium nitrate are theoretically produced if we start with 3.4 moles of Ca(NO3)2 and 2.4 moles of Li3PO4? Reaction: 3Ca(NO3)2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4)2 A) 7.2 B) 6.8 C) 1.2 D) 1.1 E) not enough information Answer: B 73. How many grams of calcium phosphate are theoretically produced if we start with 3.40 moles of Ca(NO3)2 and 2.40 moles of Li3PO4? Reaction: 3Ca(NO3)2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4)2 A) 310 B) 248 C) 1054 D) 351 E) not enough information Answer: D 74. How many grams of NO2 are theoretically produced if we start with 1.20 moles of S and 9.90 moles of HNO3? Reaction: S + 6HNO3 → H2SO4 + 6NO2 + 2H2O A) 7.20 B) 331 C) 455 D) 786 E) not enough information Answer: B 75. What is the limiting reactant for the following reaction given we have 2.6 moles of HCl and 1.4 moles of Ca(OH)2? Reaction: 2HCl + Ca(OH)2 → 2H2O + CaCl2 A) Ca(OH)2 B) HCl C) H2O D) CaCl2 E) not enough information Answer: B 76. What is the excess reactant for the following reaction given we have 2.6 moles of HCl and 1.4 moles of Ca(OH)2? Reaction: 2HCl + Ca(OH)2 → 2H2O + CaCl2 A) Ca(OH)2 B) HCl C) H2O D) CaCl2 E) not enough information Answer: A 77. How many moles of calcium chloride are theoretically produced for the following reaction given we have 2.6 moles of HCl and 1.4 moles of Ca(OH)2? Reaction: 2HCl + Ca(OH)2 → 2H2O + CaCl2 A) 0.7 B) 1.0 C) 1.4 D) 1.3 E) not enough information Answer: D 78. How many grams of water are theoretically produced for the following reaction given we have 2.6 moles of HCl and 1.4 moles of Ca(OH)2? Reaction: 2HCl + Ca(OH)2 → 2H2O + CaCl2 A) 25.2 B) 50.4 C) 46.8 D) 103.6 E) not enough information Answer: C 79. In order to determine the limiting reactant in a particular reaction, one must know each of the following EXCEPT A) the mass of each reactant present. B) the molar mass of each reactant present. C) the coefficient of each reactant in a balanced equation. D) the mass of each product formed. Answer: D 80. What is the limiting reactant for the reaction below given that you start with 2.50 grams C and 2.50 grams SiO2? Reaction: C + SiO2 → SiC + O2 A) C B) SiO2 C) SiC D) O2 E) There is no limiting reactant. Answer: B 81. What is the limiting reactant for the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3 A) Al B) O2 C) Al2O3 D) both Al and O2 E) not enough information Answer: A 82. What is the excess reactant for the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3 A) Al B) O2 C) Al2O3 D) both Al and O2 E) not enough information Answer: B 83. How many moles of aluminum oxide are produced according to the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3 A) 0.396 B) 0.185 C) 0.741 D) 5.00 E) not enough information Answer: B 84. How many grams of aluminum oxide are produced according to the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3 A) 40.4 B) 5.00 C) 0.185 D) 18.9 E) not enough information Answer: D 85. If 16.0 grams of aluminum oxide were actually produced, what is the percent yield of the reaction below given that you start with 10.0 g of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3 A) 75.0% B) 100% C) 84.7% D) 39.6% E) not enough information Answer: C 86. A sample of 8.5 g NH3 on oxidation produces 4.5 g of NO. Calculate the percent yield. Reaction: 4 NH3 + 5 O2 → 4 NO + 6 H2O A) 15 % B) 30% C) 60% D) 70% E) none of the above Answer: B 87. The reaction for the oxidation of NH3 is given as: 4 NH3 + 5 O2 → 4 NO + 6 H2O Under certain conditions the reaction will proceed at 29.8% yield of NO. How many grams of NH3 must be made to react with excess oxygen to yield 70.5 g of NO? A) 134 B) 237 C) 21.0 D) 2.37 E) none of the above Answer: A 88. How many grams of the excess reactant are left over according to the reaction below given that you start with 10.0 g of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3 A) 8.90 B) 10.1 C) 1.1 D) 14.6 E) not enough information Answer: B 89. How many moles of NH3 can be produced by the reaction of 2.00 g of N2 with 3.00 g H2? Reaction: N2(g) + 3 H2(g) → 2 NH3(g) A) 0.143 B) 0.0567 C) 0.235 D) 1.00 E) none of the above Answer: A 90. Calculate the maximum number of grams of NH3 that can be produced by the reaction of 2.00 g of N2 with 3.00 g H2. Reaction: N2(g) + 3 H2(g) → 2 NH3(g) A) 0.964 B) 2.43 C) 4.00 D) 17.0 E) none of the above Answer: B 91. A 24.0 g sample of nitrogen gas reacts with an excess of hydrogen gas to give an actual yield of 3.85 g NH3. What is the percent yield for this reaction? Reaction: N2(g) + 3 H2(g) → 2 NH3(g) A) 86.8% B) 73.6% C) 26.4% D) 13.2% E) none of the above Answer: D 92. Which is the excess reactant in the following reaction given that you start with 15.5 g of Na2S and 12.1 g CuSO4? Reaction: Na2S + CuSO4 → Na2SO4 + CuS A) Na2S B) CuSO4 C) Na2SO4 D) CuS E) not enough information Answer: A 93. Which is the limiting reactant in the following reaction given that you start with 15.5 g of Na2S and 12.1 g CuSO4? Reaction: Na2S + CuSO4 → Na2SO4 + CuS A) Na2S B) CuSO4 C) Na2SO4 D) CuS E) not enough information Answer: B 94. Which is the limiting reactant in the following reaction given that you start with 42.0 g of CO2 and 99.9 g KOH? Reaction: CO2 + 2KOH → K2CO3 + H2O A) K2CO3 B) H2O C) CO2 D) KOH E) not enough information Answer: D 95. What is the theoretical yield in grams of CuS for the following reaction given that you start with 15.5 g of Na2S and 12.1 g CuSO4? Reaction: Na2S + CuSO4 → Na2SO4 + CuS A) 0.0758 B) 0.198 C) 18.93 D) 7.25 E) not enough information Answer: D 96. What is the percent yield of CuS for the following reaction given that you start with 15.5 g of Na2S and 12.1 g CuSO4? The actual amount of CuS produced was 3.05 g. Reaction: Na2S + CuSO4 → Na2SO4 + CuS A) 16.1% B) 42.1% C) 18.93% D) 7.25% E) not enough information Answer: B 97. How many grams of the excess reactant remain assuming the reaction goes to completion and that you start with 15.5 g of Na2S and 12.1 g CuSO4? Reaction: Na2S + CuSO4 → Na2SO4 + CuS A) 0.05 B) 15.45 C) 9.58 D) 5.92 E) not enough information Answer: C 98. Consider the reaction: 2 Al + 3Br2 → 2 AlBr3 Suppose a reaction vessel initially contains 5.0 mole Al and 6.0 mole Br2. What is in the reaction vessel once the reaction has occurred to the fullest extent possible? A) 1.0 mole Al; 0 mole Br2; 4.0 mole AlBr3 B) 0 mole Al; 0 mole Br2; 11.0 mole AlBr3 C) 2.0 mole Al; 3.0 mole Br2; 2.0 mole AlBr3 D) 0 mole Al; 1.0 mole Br2; 4.0 mole AlBr3 E) none of the above Answer: A 99. The reaction of one mole of nitrogen gas with three moles of hydrogen gas releases 92 kJ of thermal energy to the surroundings. Which of the following is TRUE? A) This reaction is exothermic. B) This reaction has a negative enthalpy of reaction. C) Complete reaction of two moles of nitrogen gas would release 184 kJ of thermal energy in this reaction. D) All of the above are true. E) None of the above are true. Answer: D 100. Consider the following reaction: 2 Mg + O2 → 2 MgO △H rxn = -1203 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg. A) -1203 kJ B) -2406 kJ C) -601.5 kJ D) -4812 kJ E) none of the above Answer: B 101. Consider the following equation: CO + 2 H2 → CH3OH △Hrxn = -128 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 8.08 g H2. A) -1024 kJ B) -1034 kJ C) -256 kJ D) -512 kJ E) none of the above Answer: C Algorithmic Questions 102. How many moles of water are needed to react with 2.2 moles of Li2O? Given: Li2O + H2O → 2 LiOH A) 4.4 B) 1.1 C) 1.5 D) 2.2 E) none of the above Answer: D 103. How many grams of water are needed to react with 27.2 grams of Li2O? Given: Li2O + H2O → 2 LiOH A) 0.910 B) 16.4 C) 1.51 D) 38.94 E) none of the above Answer: B 104. If the theoretical yield of the reaction below corresponds to 99.2 g and the actual yield was 60.9 g, calculate the percent yield. Given: Li2O + H2O → 2 LiOH A) 16.0 % B) 71.8 % C) 38.0 % D) 61.4 % E) none of the above Answer: D 105. If the theoretical yield of the reaction below corresponds to 25.3 g and the percent yield of the reaction is known to be reproducibly 81.1%, calculate the actual yield. Given: Li2O + H2O → 2 LiOH A) 20.5 g B) 48.9 g C) 45.8 g D) 81.1 g E) none of the above Answer: A 106. Starting with 156 g Li2O and 33.3 g H2O, decide which reactant is present in limiting quantities. Given: Li2O + H2O → 2 LiOH A) lithium oxide B) water C) lithium hydroxide D) insufficient data E) none of the above Answer: B Test Bank for Introductory Chemistry Nivaldo J. Tro 9780321741028, 9780321687937, 9781256112938, 9781256161066, 9780134302386, 9780321910073
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