Test Bank for Chemical Principles 8th Edition by Steven S. Zumdahl

Chapter 03 - Stoichiometry 1. Bromine exists naturally as a mixture of bromine-79 and bromine-81 isotopes. An atom of bromine-79 contains a. 79 protons, 79 electrons, and 35 neutrons. b. 35 protons, 44 neutrons, and 35 electrons. c. 44 protons, 44 electrons, and 35 neutrons. d. 34 protons and 35 electrons only. e. 35 protons, 79 neutrons, and 35 electrons. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b 1 easy 3.1 atomic theory of matter | early atomic theory | general chemistry | isotope 2. The atomic mass of rhenium is 186.2. Given that 37.1% of natural rhenium is rhenium-185, what is the other stable isotope? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. b. c. d. e. b 1 easy 3.1 atomic theory of matter | early atomic theory | general chemistry | isotope 3. Consider the new element moonium, atomic number 118, atomic mass 273.2 g. The nucleus of an atom of moonium-273 contains a. 118 protons, 118 alpha particles. b. 118 protons, 155 neutrons. c. 118 protons, 273neutrons. d. 118protons, 155 neutrons, 118 electrons. e. 118protons, 118neutrons. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b 1 easy 3.1 atomic theory of matter | early atomic theory | general chemistry | nuclear structure 4. For a new element, 60.54% is an isotope with mass 282.1 amu, 3.28% is an isotope with mass 283.2 amu, Copyright Cengage Learning. Powered by Cognero. Page 1 Chapter 03 - Stoichiometry and 36.18% is an isotope with mass 284.6 amu. Calculate the average atomic mass of this new element. a. 283.3 amu ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 849.9 amu c. 282.1 amu d. 283.0 amu e. 314.5 amu easy 3.1 atomic theory of matter | atomic weight | early atomic theory | general chemistry | relative atomic mass d 1 5. The average mass of a boron atom is 10.81. If you were able to isolate a single boron atom, what is the chance that you would randomly get an atom with mass 10.81? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. greater than 50% b. 0% c. 0.81% d. 10.81% e. about 11% b 1 easy 3.1 atomic theory of matter | atomic weight | early atomic theory | general chemistry | relative atomic mass 6. Indium has atomic number 49 and atomic mass 114.8 g. Naturally occurring indium contains a mixture of indium-112 and indium-115 in an atomic ratio of approximately ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 75/25. b. 25/75. c. 6/94. d. 50/50. e. 94/6. c 1 moderate 3.1 atomic theory of matter | early atomic theory | general chemistry | isotope 7. Boron naturally occurs in two isotopic forms. The more common isotope is 11B (atomic mass 11.01 amu), which is 80.00% abundant. The average atomic mass of boron is 10.81. What is the mass of the other isotope? Copyright Cengage Learning. Powered by Cognero. Page 2 Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 10.91 amu. b. 10.01 amu. c. 10.81 amu. d. 11.00 amu. e. 11.01 amu. moderate 3.1 atomic theory of matter | atomic weight | early atomic theory | general chemistry | relative atomic mass ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 0.269 mol c. 0.118 mol d. 0.577 mol e. 0.0780 mol b 1 easy 3.2 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry b 1 8. A sample of iron weighing 15.0 g contains how many moles of iron atoms? a. 3.72 mol 9. A single atom of an element weighs 5.81 × 10–23 g. Identify the isotope. 35Cl 103Rh 80Br ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 45Sc e. none of these a 1 moderate 3.2 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry a. b. c. d. 10. Iron is biologically important in the transport of oxygen by red blood cells from the lungs to the various organs of the body. In the blood of an adult human, there are approximately 2.60 × 1013 red blood cells with a total of 2.90 g of iron. On the average, how many iron atoms are present in each red blood cell? (molar mass for Fe = 55.85 g) Copyright Cengage Learning. Powered by Cognero. Page 3 Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: c 1 easy 3.2 3.3 ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a 1 easy 3.3 general chemistry | mass and moles of substance | molecular weight | stoichiometry –10 8.33 × 10 b 1 moderate 3.2 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry a. b. c. d. e. 1.20 × 109 –2 5.19 × 10 3.12 × 1022 2.60 × 1013 11. An alkali metal oxide contains 83.01% metal by mass. Determine the identity of the metal. a. b. c. d. e. Cs Li K Na Rb general chemistry | mass percentage | stoichiometry determining chemical formulas | 12. What is the molar mass of ethanol (C2H5OH)? a. 46.07 b. 62.07 c. 45.07 d. 38.90 e. 34.17 13. For which of the following compounds does 1.0 g represent 2.27 × 10–2 mol? a. H2O Copyright Cengage Learning. Powered by Cognero. Page 4 b. C2H6 Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: c. NH3 d. CO2 e. CO d 1 easy 3.3 general chemistry | mass and moles of substance | molecular weight | stoichiometry 14. Which compound has the smallest molar mass? a 1 easy 3.3 general chemistry | mass and moles of substance | molecular weight | stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 16. Calculate the a. b. c. d. c 1 easy 3.3 general chemistry | mass and moles of substance | molecular weight | stoichiometry molar mass of a sample if a single molecule weighs 5.34 × 10–23 g. 12.0 g/mol –23 5.34 × 10 g/mol 1.13 × 1046 g/mol 32.2 g/mol Copyright Cengage Learning. Powered by Cognero. Page 5 a. b. c. d. C2H6 CH3Cl CO2 C2H4O e. none of these 15. For which compound does 0.256 mole weigh 12.9 g? a. b. c. d. e. C2H4O2 C2H6 CH3Cl CO2 C2H4O Chapter 03 - Stoichiometry e. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: none of these d 1 easy 3.3 general chemistry | mass and moles of substance | molecular weight | stoichiometry 17. How many moles of P4 molecules molecules are in 145.2 g of phosphorus? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 1.10 × 10 g d. 208.22 g e. 1.00 g b 1 moderate 3.3 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry a. b. c. d. e. 1.172 mol 1.452 × 101 mol 4.688 mol 2.411 × 101 mol 1.799 × 104 mol a 1 easy 3.3 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 18. What is the mass (in grams) of one molecule of phosphorus pentachloride? a. b. c. 1.25 × 1026 g –22 3.46 × 10 g –22 19. How many molecules of ammonia are present in 6.9 g of ammonia? –25 6.7 × 10 4.1 × 101 8.3 × 1023 4.2 × 1024 2.4 × 1023 ANSWER: e Copyright Cengage Learning. Powered by Cognero. a. b. c. d. e. Page 6 Chapter 03 - Stoichiometry POINTS: DIFFICULTY: TOPICS: KEYWORDS: 1 moderate 3.3 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 20. How many atoms of hydrogen are present in 4.0 g of ammonia? 7.8 × 1024 0.70 c 1 moderate 3.3 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. b. c. d. e. 4.2 × 1023 –24 1.2 × 10 1.8 × 1024 21. The mass of 0.82 mol of a diatomic molecule is 131.3 g. Identify the molecule. a. Xe ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: e 1 moderate 3.3 general chemistry | mass and moles of substance | molecular weight | stoichiometry b. c. d. e. Cl2 I2 F2 Br2 22. Roundup, an herbicide manufactured by Monsanto, has the formula C3H8NO5P. How many moles of molecules are there in a 500.-g sample of Roundup? a. 84.5 b. 2.96 c. 0.338 d. 1.75 e. none of these ANSWER: b POINTS: 1 DIFFICULTY: moderate Copyright Cengage Learning. Powered by Cognero. Page 7 Chapter 03 - Stoichiometry TOPICS: 3.3 KEYWORDS: general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 23. What mass of styrene (molar mass 104.1 g/mol) contains 4.50 × 1020 molecules of styrene? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. b. c. 0.00778 g –2 7.78 × 10 g 7.48 × 104 g –4 d. e. a 1 moderate 3.3 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 7.48 × 10 g –3 7.48 × 10 g 24. Phosphorus has the molecular formula P4 and sulfur has the molecular formula S8. How many grams of phosphorus contain the same number of molecules as 6.41 g of sulfur? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 6.19 g b. 6.41 g c. 3.21 g d. 3.10 g e. none of these d 1 moderate 3.3 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 25. The molar mass of the insecticide dibromoethane is 187.9 g/mol. Its molecular formula is C2H4Br2. How many atoms of carbon are in a sample of dibromoethane weighing 1.879 g? a. none of these 1.204 × 1022 6.022 × 100.21 6.022 × 1021 12.04 × 1044 ANSWER: b POINTS: 1 DIFFICULTY: moderate TOPICS: 3.3 Copyright Cengage Learning. Powered by Cognero. b. c. d. e. Page 8 Chapter 03 - Stoichiometry KEYWORDS: general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 26. A given sample of xenon fluoride contains molecules of a single type, XeFn, where n is some whole number. Given that 9.03 × 1020 molecules of XeFn weigh 0.311 g, calculate n. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 2 b. 4 c. 1 d. none of these b 1 moderate 3.3 determining chemical formulas | empirical formula | general chemistry | stoichiometry 27. NaHCO3 is the active ingredient in baking soda. How many grams of oxygen are in 0.36 g of NaHCO3? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. b. c. d. e. b 1 moderate 3.3 general chemistry | 0.0043 g 0.21 g 0.013g 0.069 g 1.1 g mass and moles of substance | mole | mole calculations | stoichiometry 28. The empirical formula of sugar is CH2O and its molar mass is 180.2 g/mole. If one teaspoon of sugar weighs 3.50 g, how many moles of sugar and how many molecules of sugar are present? 0.0194 mole, 3.24 × 1026 molecules 0.0295 mole, 1.78 × 1022 molecules 0.0583 mole, 3.51 × 1022 molecules 0.0194 mole, 1.17 × 1022 molecules 0.117 mole, 7.03 × 1022 molecules d 1 moderate 3.3 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry a. b. c. d. e. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: Copyright Cengage Learning. Powered by Cognero. Page 9 Chapter 03 - Stoichiometry 29. Compound X2Y is 60% X by mass. Calculate the percent Y by mass of the compound X2Y2. a. 30% ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 80% c. 40% d. 20% e. 60% determining chemical formulas | general chemistry | mass percentage | stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: d 1 moderate 3.3 3.5 e 1 moderate 3.3 3.4 30. Cortisone consists of molecules, each of which contains 21 atoms of carbon (plus other atoms). The mass percentage of carbon in cortisone is 69.98%. What is the molar mass of cortisone? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 287.6 g/mol b. 360.4 g/mol c. 176.5 g/mol d. 252.2 g/mol e. 312.8 g/mol moderate 3.3 3.5 general chemistry | mass and moles of substance | molecular weight | stoichiometry b 1 31. An oxybromate compound, NaBrOx, where x is a whole number, is analyzed and found to contain 52.95% Br by mass. What is x? a. 0 b. 1 c. 2 d. 3 e. 4 determining chemical formulas | empirical formula | general chemistry | stoichiometry 32. Which of the following contains the greatest percentage of nitrogen by mass? Copyright Cengage Learning. Powered by Cognero. Page 10 Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a 1 easy 3.4 determining chemical formulas | general chemistry | mass percentage | stoichiometry a. b. HCN c. d. e. NH3 C6H4N3O6 N2O NO2 33. The molar mass of the insecticide dibromoethane is 187.9. Its molecular formula is C2H4Br2. What percent by mass of bromine does dibromoethane contain? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 50.0% b. 37.8% c. 42.5% d. 89.3% e. 85.0% e 1 easy 3.4 determining chemical formulas | general chemistry | mass percentage | stoichiometry 34. A substance contains 3.024 g hydrogen, 30.97 g phosphorus, and 64.00 g oxygen. How many grams of oxygen are in an 85.00-g sample of the substance? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 64.00 g b. 130.1 g c. 16.00 g d. 55.51 g e. none of these d 1 moderate 3.4 determining chemical formulas | general chemistry | mass percentage | stoichiometry 35. What is the percent by mass of hydrogen in ammonium acetate? Copyright Cengage Learning. Powered by Cognero. Page 11 a. b. 7.07% 5.23% Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: c. 14.3% d. 3.92% e. 9.15% e 1 moderate 3.4 general chemistry | mass and moles of substance | mass percentage | stoichiometry 36. A hydrate of copper(II) sulfate is 25.5% copper by mass. How many water molecules are there for each unit of copper(II) sulfate? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 1 b. 2 c. 3 d. 4 e. 5 e 1 moderate 3.4 determining chemical formulas | empirical formula | general chemistry | stoichiometry 37. Which of the following compounds has the same percent composition by mass as styrene, C8H8? a. b. c. d. e. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: cyclobutadiene, C4H4 α-ethyl naphthalene, C12H12 acetylene, C2H2 benzene, C6H6 all of these e 1 moderate 3.4 determining chemical formulas | general chemistry | mass percentage | stoichiometry 38. Find the percent sulfur (atoms) by mass in sodium sulfide. Copyright Cengage Learning. Powered by Cognero. Page 12 a. b. c. d. e. 52.1% 58.2% 41.1% 74.4% 73.6% Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: c 1 moderate 3.4 determining chemical formulas | general chemistry | mass percentage | stoichiometry 39. You find a compound composed only of element X and hydrogen, and you know that it is 91.33% element X by mass. Each molecule has 2.67 times as many H atoms as X atoms. What is element X? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. Cu b. Si c. Cl d. C e. Ne b 1 difficult 3.4 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 40. A mixture of NaCl and NaNO3 is 31.7% sodium by mass. What is the approximate percent of NaCl in this mixture? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 32% b. 30% c. 38% d. 36% e. 34% c 1 difficult 3.4 general chemistry | mass and moles of substance | mass percentage | stoichiometry 41. TNT consists of carbon, nitrogen, oxygen, and hydrogen. It is 37.02% carbon by mass, 18.49% nitrogen by mass, and 42.27% oxygen by mass. The molar mass of TNT is between 210 g/mol and 245 g/mol. What is the molecular formula for TNT? a. b. c. d. e. none of these ANSWER: c Copyright Cengage Learning. Powered by Cognero. C4H7N6O6 C6H4N3O6 C7H5N3O6 C8H12N3O4 Page 13 Chapter 03 - Stoichiometry POINTS: DIFFICULTY: TOPICS: KEYWORDS: 1 difficult 3.4 3.5 determining chemical formulas | general chemistry | molecular formula | stoichiometry 42. Caffeine consists of carbon, hydrogen, oxygen, and nitrogen. When 0.1920 g of caffeine is burned in an excess of oxygen, 0.3482 g of carbon dioxide and 0.0891 g water are formed. Caffeine is 28.84% nitrogen by mass. Its molar mass is between 190 and 200 g/mol. What is the formula for caffeine? b 1 difficult 3.4 3.5 determining chemical formulas | general chemistry | molecular formula | stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. b. c. d. C6H4N4O4 C8H10N4O2 C4H5N2O C3H2N2O2 e. none of these formula of a group of compounds is CHCl. Lindane, a powerful insecticide, is a member of 43. The empirical this group. The molar mass of lindane is 290.8. How many atoms of carbon does a molecule of lindane contain? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 6 b. 4 c. 3 d. 8 e. 2 a 1 easy 3.5 determining chemical formulas | general chemistry | molecular formula | stoichiometry 44. The empirical formula of styrene is CH; its molar mass is 104.1. What is the molecular formula of styrene? Copyright Cengage Learning. Powered by Cognero. Page 14 a. b. c. d. e. none of these C2H4 C8H8 C6H6 C10H12 Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b 1 easy 3.5 determining chemical formulas | general chemistry | molecular formula | stoichiometry 45. What is the empirical formula of a hydrocarbon (a compound that consists of only carbon and hydrogen) that contains 81.7% carbon by mass? b 1 moderate 3.5 determining chemical formulas | empirical formula | general chemistry | stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. b. c. d. C5H12 C3H8 C4H10 C2H6 e. none of these 46. The mass percent of iron in an iron oxide is 77.7%. Find the empirical formula. a. b. c. d. e. d ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 1 moderate 3.5 determining chemical formulas | empirical formula | general chemistry | stoichiometry Fe3O2 Fe3O4 Fe2O3 FeO none of these 47. Adipic acid contains 49.32% C, 43.84% O, and 6.85% H by mass. What is the empirical formula? a. b. c. d. e. ANSWER: b POINTS: 1 Copyright Cengage Learning. Powered by Cognero. Page 15 C2H5O4 C3H5O2 C2HO3 C3H3O4 C3HO3 Chapter 03 - Stoichiometry DIFFICULTY: TOPICS: KEYWORDS: moderate 3.5 determining chemical formulas | empirical formula | general chemistry | stoichiometry 48. Vitamin C contains the elements C, H, and O. It is known to contain 40.9% C and 4.58% H by mass. The molar mass of vitamin C has been found to be about 180. The molecular formula for vitamin C is a 1 moderate 3.5 determining chemical formulas | general chemistry | molecular formula | stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: ANSWER: a POINTS: 1 Copyright Cengage Learning. Powered by Cognero. Page 16 a. b. c. d. C6H8O6 C4H6O4 C3H4O3 C2H3O2 e. none of these 49. A 2.00-g sample of an oxide of bromine is converted to 2.936 g of AgBr. Calculate the empirical formula of the oxide. (molar mass for AgBr = 187.78) a. b. BrO c. d. e. none of these a 1 difficult 3.5 determining chemical formulas | empirical formula | general chemistry | stoichiometry BrO3 BrO2 Br2O 50. A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.8635 g of CO2 and 0.1767 g of H2O. What is the empirical formula of the compound? a. b. c. d. e. CHO C3H3O2 C2H2O C6H3O2 C3H6O2 Chapter 03 - Stoichiometry DIFFICULTY: TOPICS: KEYWORDS: difficult 3.5 determining chemical formulas | empirical formula | general chemistry | stoichiometry 51. When the equation C6H14 + O2 → CO2 + H2O is balanced with the smallest set of integers, the sum of the coefficients is ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: c 1 moderate 3.6 3.7 a. 28 b. 33 c. 47 d. 4 e. 40 balancing chemical equation | chemical equation | early atomic theory | general chemistry 52. Consider the following unbalanced equation: C4H10 +O2 →CO2 +H2O For every 1.0 mol of C4H10, ___ mol of O2 is required. a. 1.0 ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 8.0 c. 13.0 d. 6.5 e. none of these d 1 easy 3.7 balancing chemical equation | chemical equation | early atomic theory | general chemistry 53. wPCl5 + xH2O → yPOCl3 + zHCl When the equation is properly balanced, what are the coefficients? ANSWER: a a. b. c. d. e. w = 1, x = 1, y = 1, z = 2 w = 2, x = 2, y = 2, z = 2 w = 1, x = 2, y = 2, z = 4 w = 2, x = 2, y = 2, z = 4 none of these Copyright Cengage Learning. Powered by Cognero. Page 17 Chapter 03 - Stoichiometry POINTS: DIFFICULTY: TOPICS: KEYWORDS: 1 easy 3.7 balancing chemical equation | chemical equation | early atomic theory | general chemistry 54. What is the subscript of aluminum in the formula of aluminum phosphate? a. 3 ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b 1 easy 3.7 ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 1, 2, 2, 2 b. 1, 2, 1, 6 c. 1, 1, 1, 6 d. 6, 2, 1, 1 e. 2, 4, 2, 6 b 1 easy 3.7 balancing chemical equation | chemical equation | early atomic theory | general chemistry b. 1 c. 2 d. 0 e. 4 chemical formula | chemical substance | early atomic theory | general chemistry | ionic substance 55. Give (in order) the correct coefficients to balance the following reaction: H2SnCl6 + H2S → SnS2 + HCl 56. In the balanced equation for the reaction [A]P4O6(s) + [B]H2O(l) → [C]H3PO3(aq) if [A] equals 2, the coefficient [C] equals a. 6 b. 4 c. 2 d. 10 e. none of these ANSWER: e POINTS: 1 Copyright Cengage Learning. Powered by Cognero. Page 18 Chapter 03 - Stoichiometry DIFFICULTY: TOPICS: KEYWORDS: easy 3.7 balancing chemical equation | chemical equation | general chemistry | stoichiometry 57. Which of the following equations correctly describes the combustion of CH4 and O2 to produce water (H2O) and carbon dioxide (CO2)? a. b. c. d. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: CH4 + (1/2)O2 → CO2 + H2O CH4 +2O2 →CO2 +2H2O CH4 +3O2 →2CO2 +H2O CH4 +O2 →CO2 +2H2O b 1 easy 3.7 chemical equation | early atomic theory | general chemistry | writing equation 58. When the following equation is balanced, what is the sum of the coefficients? Al2(SO4)3 + Ca(OH)2 → Al(OH)3 + CaSO4 ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 10 b. 8 c. 4 d. 9 e. 3 d 1 easy 3.7 balancing chemical equation | chemical equation | early atomic theory | general chemistry 59. When the equation FeCr2O4 + K2CO3 + O2 → K2CrO4 + Fe2O3 + CO2 is balanced with the smallest set of integers, the sum of the coefficients is ANSWER: d POINTS: 1 DIFFICULTY: moderate TOPICS: 3.7 Copyright Cengage Learning. Powered by Cognero. Page 19 a. 9 b. 15 c. 6 d. 37 e. 24 Chapter 03 - Stoichiometry KEYWORDS: balancing chemical equation | chemical equation | early atomic theory | general chemistry 60. Potassium forms an oxide containing 1 oxygen atom for every 2 atoms of potassium. What is the coefficient of oxygen in the balanced equation for the reaction of potassium with oxygen to form this oxide? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 0 b. 1 c. 2 d. 3 e. 4 b 1 moderate 3.7 balancing chemical equation | chemical equation | early atomic theory | general chemistry 61. How many moles of sodium phosphate are required to react completely with 3.0 mol of calcium nitrate to form sodium nitrate and calcium phosphate? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 2.0 mol b. 3.0 mol c. 1.0 mol d. 1.5 mol e. 4.5 mol a 1 moderate 3.7 general chemistry | molar interpretation | stoichiometry | stoichiometry calculation 62. When the equation NH3 + O2 → NO + H2O is balanced with the smallest set of integers, the sum of the coefficients is ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 4 b. 24 c. 12 d. 14 e. 19 e 1 moderate 3.7 general chemistry | molar interpretation | stoichiometry | stoichiometry calculation Copyright Cengage Learning. Powered by Cognero. Page 20 Chapter 03 - Stoichiometry 63. Indium reacts with chlorine to form InCl3. In the balanced equation for this reaction, the coefficient of the indium trichloride ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: is ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 2.0 c. 3.0 d. 1.0 e. none of these c 1 moderate 3.7 general chemistry | molar interpretation | stoichiometry | stoichiometry calculation a. 6 b. 4 c. 2 d. 3 e. 1 c 1 moderate 3.7 balancing chemical equation | chemical equation | early atomic theory | general chemistry 64. Consider the following unbalanced equation: KO2 +H2O→KOH+O2 +H2O2 For every 3.0 mol of KO2, ___ mol of H2O is needed for a complete reaction. a. 6.0 65. Baking powder, a mixture of cream of tartar (KHC4H4O6, molar mass 188 g/mol) and baking soda (NaHCO3, molar mass 84.0 g/mol), undergoes the following reaction at baking temperatures: KHC4H4O6 + NaHCO3 → KNaC4H4O6 + H2O + CO2 (The CO2 makes the cake rise.) A recipe calls for two level teaspoons (a total of 8.0 g) of cream of tartar. How much baking soda must be added for both materials to react completely? a. 8.0 g b. 0.45 g c. 3.6 g d. 18 g e. none of these ANSWER: c POINTS: 1 DIFFICULTY: moderate Copyright Cengage Learning. Powered by Cognero. Page 21 Chapter 03 - Stoichiometry TOPICS: 3.7 KEYWORDS: amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 66. A reaction occurs between sodium carbonate and hydrochloric acid producing sodium chloride, carbon dioxide, and water. The correct set of coefficients, respectively, for the balanced reaction is ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 5, 10, 10, 5, 5. b. 1, 2, 2, 1, 1. c. 8, 6, 5, 10, 5. d. 3, 6, 6, 3, 4. e. none of these b 1 difficult 3.7 balancing chemical equation | chemical equation | early atomic theory | general chemistry 67. A 6.32-g sample of potassium chlorate was decomposed according to the following equation: 2KClO3 → 2KCl + 3O2 How many moles of oxygen are formed? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 0.051 mol b. 0.0774 mol c. 0.0344 mol d. 1.65 mol e. none of these b 1 moderate 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 68. Sulfuric acid may be produced by the following process: 4FeS2 + 11O2 → 2Fe2O3 + 8SO2 2SO2 + O2 → 2SO3 SO3 + H2O → H2SO4 How many moles of H2SO4 will be produced form 5.00 mol of FeS2? a. 12.2 mol b. 20.0 mol c. 6.11 mol d. 10.0 mol Copyright Cengage Learning. Powered by Cognero. Page 22 Chapter 03 - Stoichiometry e. 5.00 mol ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: d 1 moderate 3.8 general chemistry | molar interpretation | stoichiometry | stoichiometry calculation 69. Consider the following reaction: CH4(g) + 4Cl2(g) → CCl4(g) + 4HCl(g) What mass of CCl4 is formed by the reaction of 8.00 g of methane with an excess of chlorine? a. 14.2 g ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 7.10 g c. 76.7 g d. 1.42 g e. none of these c 1 moderate 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 70. When rubidium metal is exposed to air, one atom of rubidium, Rb, combines with two atoms of oxygen. If 1.75 g of rubidium is exposed to air, what will be the mass of the product in grams? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 0.655 g b. 1.37 g c. 0.328 g d. 2.41 g e. 2.08 g d 1 moderate 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 71. Iron is produced from its ore by the following reactions: 2C(s) + O2(g) → 2CO(g) Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g) How many moles of C(s) are needed to produce 2.4 mol Fe(s)? a. 3.6 mol C b. 2.4 mol C c. 5.0 mol C Copyright Cengage Learning. Powered by Cognero. Page 23 Chapter 03 - Stoichiometry d. 1.6 mol C ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a 1 moderate 3.8 general chemistry | molar interpretation | stoichiometry | stoichiometry calculation 72. Consider the following two reactions. Mg + 2HCl→ MgCl2 + H2 2H2 + O2→ 2H2O How much water (in grams) is a. b. c. d. e. produced from 10.0 g of Mg? 3.71 g 18.0 g 7.41 g 1.85 g none of these ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: c 1 difficult 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 73. The refining of aluminum from bauxite ore (which contains 50.% Al2O3 by mass) proceeds by the overall reaction 2Al2O3 + 3C → 4Al + 3CO2. How much bauxite ore is required to give the 5.0 × 1013 g of aluminum produced each year in the United States? (Assume 100% conversion.) 1.9 × 1014 g 7.6 × 1014 g 1.3 × 1013 g 5.3 × 1013 g ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a 1 difficult 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation a. b. c. d. 74. One commercial system removes SO2 emissions from smoke at 95.0°C by the following set of balanced reactions: SO2(g) + Cl2 → SO2Cl2(g) SO2Cl2 + 2H2O → H2SO4 + 2HCl H2SO4 + Ca(OH)2 → CaSO4(s) + 2H2O Copyright Cengage Learning. Powered by Cognero. Page 24 Chapter 03 - Stoichiometry Assuming the process is 95.0% efficient, how many grams of CaSO4 may be produced from 1.00 × 102 g of SO2 (molar masses: SO2, 64.1 g/mol; CaSO4, 136 g/mol)? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 47.1 g b. 212 g c. 202 g d. 87.2 g e. 44.8 g c 1 difficult 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 75. How many grams of Ca(NO3)2 can be produced by reacting excess HNO3 with 7.40 g of Ca(OH)2? a. 10.2 g ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 16.4 g c. 7.40 g d. 8.22 g e. 32.8 g b 1 difficult 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 76. How many grams of H2O react to form water? will be formed when 39.0 g H2 is mixed with 49.6 g O2 and allowed to completely 88.6 g 55.8 g 27.9 g 351 g 59.1 g ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. b. c. d. e. moderate 3.8 3.9 b 1 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 77. The limiting reactant in a reaction a. is the reactant for which you have the least number of moles. Copyright Cengage Learning. Powered by Cognero. Page 25 Chapter 03 - Stoichiometry b. has the lowest coefficient in a balanced equation. c. has the lowest ratio of coefficient in the balanced equation to moles available. d. has the lowest ratio of moles available to coefficient in the balanced equation. e. none of these ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: d 1 easy 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 78. 29.4 g of Al and 25.0g of Br2 react according to the following equation: 2Al + 3Br2 → 2AlBr3 What mass of AlBr3 is formed, assuming 100% yield? a. 62.6 g ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 79. In the reaction 2A+3B → b. 291 g c. 27.8 g d. 54.4 g e. 41.7 g c 1 moderate 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation C 4.0 mol A react with 4.0 mol B. Which reactant is limiting? a. A is limiting because there are 2 mol of it but 4.0 mol are needed. b. B is limiting because there are 4.0 mol of it but 6.0 mol are needed. c. A is limiting because 2 is smaller than 3 (the coefficients in the balanced equation). d. Neither is limiting because equal amounts (4.0 mol) of each reactant are used. e. B is limiting because 3 is larger than 2 (the coefficients in the balanced equation). ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b 1 moderate 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 80. A 7.66-g sample of AgNO3 is reacted with BaCl2 according to the equation 2AgNO3(aq) + BaCl2(aq) → 2AgCl(s) + Ba(NO3)2(aq) to give 4.34 g of AgCl. What is the percent yield of AgCl? Copyright Cengage Learning. Powered by Cognero. Page 26 Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 47.8% b. 56.7% c. 67.2% d. 33.6% e. 20.1% c 1 moderate 3.9 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation 81. When 10.0 g of hydrogen water? gas reacts with 10.0 g of oxygen gas to form water, what is the theoretical yield of 10.6 g 20.0 g 11.3 g 10.0 g 89.4 g ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: c 1 moderate 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation a. b. c. d. e. 82. Consider the following reaction: CH4(g) + 4Cl2(g) → CCl4(g) + 4HCl(g) What mass of CCl4 will be formed if 1.4moles of methane react with 1.4 moles of chlorine? a. 861 g ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b. 215 g c. 51.0 g d. 53.8 g e. 21.5 g d 1 moderate 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 83. In the reaction 2A + B → 3C + D 3.0 mol A and 2.0 mol B react to form 4.0 mol C. What is the percent yield of this reaction? Copyright Cengage Learning. Powered by Cognero. Page 27 Chapter 03 - Stoichiometry ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 50% b. 89% c. 100% d. 75% e. 67% b 1 moderate 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 84. SO2 reacts with H2S as follows: 2H2S+SO2 →3S+2H2O When 7.50 g of H2S reacts with 12.75 g of SO2, which statement applies? a. b. c. d. e. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 6.38 g of sulfur is formed. 1.13 g of H2S remains. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: b 1 difficult 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 0.0216 mol of H2S remains. 10.6 g of sulfur is formed. SO2 is the limiting reagent. d 1 difficult 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation of lithium is reacted with 15 g of fluorine to form lithium fluoride: 85. A 15-g sample 2Li + F2 → 2LiF. After the reaction is complete, what will be present? a. 2.16 mol lithium fluoride and 0.395 mol fluorine b. 0.789 mol lithium fluoride and 1.37 mol lithium c. 0.789 mol lithium fluoride only d. 2.16 mol lithium fluoride only e. none of these 86. Consider the electrolysis of a brine solution: Copyright Cengage Learning. Powered by Cognero. Page 28 Chapter 03 - Stoichiometry 2NaCl(aq) + H2O → Cl2(g) + H2(g) + 2NaOH(aq) A 10.0-g sample of sodium chloride was placed in 10.0 g of water. If 3.85 g of Cl2 was obtained, what was the percent yield of Cl2? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a. 95.8% b. 38.5% c. 19.3% d. 63.5% e. 19.6% d 1 difficult 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 87. Consider the following balanced equation: A(g) + 5B(g) → 3C + 4D When equal masses of A and B are reacted, which is limiting? a. If the molar mass of A is less than the molar mass of B, then B must be limiting. b. If the molar mass of A is greater than the molar mass of B, then B must be limiting. c. If the molar mass of A is less than the molar mass of B, then A must be limiting. d. If the molar mass of A is greater than the molar mass of B, then A must be limiting. e. More information is needed. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a 1 difficult 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 88. Consider the following reaction: 4NH3(g) + 7O2(g) → 4NO2(g) + 6H2O(l) Consider an experiment in which you react ammonia and oxygen. At the end of the experiment, you find that you produced 27.0 g of water, and 8.52 g of ammonia is left over. Calculate the initial mass of ammonia. Assume the reaction went to completion. ANSWER: c POINTS: 1 DIFFICULTY: difficult Copyright Cengage Learning. Powered by Cognero. Page 29 a. b. c. d. e. 34.1 g 17.0 g 25.5 g 68.0 g 10.8 g Chapter 03 - Stoichiometry TOPICS: 3.9 KEYWORDS: general chemistry | molar interpretation | stoichiometry | stoichiometry calculation 89. Consider a reaction in which two reactants make one product (for example, consider the unbalanced A + B → C). You know the following: 2.0 mol A (with an excess of B) can make a maximum of 2.0 mol C 3.0 mol B (with an excess of A) can make a maximum of 4.0 mol C If you react 2.0 mol A and 3.0 mol B, what is the maximum amount of C that can be produced? a. b. c. d. e. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 5.0 mol 6.0 mol 2.0 mol 4.0 mol More information is needed. c 1 difficult 3.9 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation the protein that transports oxygen in mammals. Hemoglobin is 0.342% Fe by mass, and 90. Hemoglobin is each hemoglobin molecule contains four iron atoms. Calculate the molar mass of hemoglobin ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 6.53 × 104 g/mol 1 moderate 3.4 general chemistry | mass and moles of substance | molecular weight | stoichiometry 91. The characteristic odor of pineapple is due to ethyl butyrate, a compound containing carbon, hydrogen, and POINTS: DIFFICULTY: TOPICS: KEYWORDS: 92. Consider the following two unbalanced equations. CH4 +O2 →CO2 +H2O H2 +O2 →H2O Suppose you carry out each reaction with the same mass of oxygen (and with an excess of CH4 and H2). In Copyright Cengage Learning. Powered by Cognero. Page 30 oxygen. Combustion of 2.78 g of ethyl butyrate leads to formation of 6.32 g of CO2 and 2.58 g of H2O. The properties of the compound suggest that the molar mass should be between 100 and 150. What is the molecular formula? ANSWER: C6H12O2 1 difficult 3.5 determining chemical formulas | general chemistry | molecular formula | stoichiometry Chapter 03 - Stoichiometry which case will you make more water, and by what factor? ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: You will make twice as much water with the second reaction. 1 moderate 3.8 general chemistry | limiting reactant | stoichiometry | stoichiometry calculation 93. A 100.0-g mixture of methane (CH4) and propane (C3H8) reacts with oxygen to make carbon dioxide and water. The carbon dioxide produced has a mass of 231.25 g. Determine the percent by mass of methane in the mixture. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 21.2% CH4 1 difficult 3.8 amounts of substances | general chemistry | stoichiometry | stoichiometry calculation Acetylsalicylic acid, or aspirin (C9H8O4), is an analgesic (pain reliever). A typical aspirin tablet contains 500.0 mg of acetylsalicylic acid. 94. Determine the molar mass of acetylsalicylic acid. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 180.2 g/mol 1 easy 3.9 general chemistry | mass and moles of substance | molecular weight | stoichiometry 95. Determine the number of moles of acetylsalicylic acid per tablet. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 2.775 × 10–3 mole/tablet 1 moderate 3.9 early atomic theory | general chemistry | mass and moles of substance | mole 96. Determine the number of molecules of acetylsalicylic acid in the tablet. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 1.671 × 1021 molecules/tablet 1 moderate 3.9 general chemistry | mass and moles of substance | mole | mole calculations | stoichiometry 97. Indium has two naturally occurring isotopes with masses given in the table below. The relative atomic mass given for antimony on the periodic table is 114.82. Copyright Cengage Learning. Powered by Cognero. Page 31 Chapter 03 - Stoichiometry Isotope 113In 115In Relative atomic mass 112.9043 114.9041 When a a. b. c. d. natural sample of indium is placed in a mass spectrometer, which of the following will be true? Three peaks will be observed at 112.9043, 114.82, and 114.9041 amu. Two peaks will be observed and the 113In will be larger. One peak will be observed at the average relative atomic mass. Two peaks will be observed and the 115In will be larger. e. ANSWER: d POINTS: 1 98. Triphenylene is an organic compound containing only carbon and hydrogen with the empirical formula C3H2. Which of the following is a possible molecular mass for triphenylene? ANSWER: POINTS: c 1 Not enough information is given to answer the problem. a. b. c. d. e. 20.0 g/mol 36.0 g/mol 228.3 g/mol 366.8 g/mol c or d could be correct 99. Sodium perbromate can be synthesized via the following reaction that gives off Xenon gas. NaBrO3 + XeF2 + H2O NaBrO4 + 2HF + Xe A reaction is started with 200.0g of NaBrO3, 200.0g of XeF2 and 100.0g of water. Assuming that the reaction goes to completion, and that all of the formed xenon gas is allowed to escape into the atmosphere, what will be the minimum mass of products and reactants remaining in the reaction vessel? a. b. c. d. e. ANSWER: POINTS: 326.4 g 174.0 g 344.9 g 154.8 g Not enough information given to answer the question 100. Sodium perbromate can be synthesized via the following reaction that gives off xenon gas. c 1 __NaBrO3 + __XeF2 + __H2O __NaBrO4 + HF + __Xe What stoichiomatric coefficients should be placed in the blanks above to balance the chemical equation? Copyright Cengage Learning. Powered by Cognero. Page 32 Chapter 03 - Stoichiometry a. b. c. d. e. 101. The _____ is ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: 1, 1, 2, 1, 2, 1 2, 2, 2, 2, 3, 2 3, 2, 1, 3, 2, 1 2, 2, 1, 2, 4, 2 None of the above defined as the number equal to the a. angstrom b. bolt c. mole d. kelvin e. candela ANSWER: POINTS: e 1 number of carbon atoms in exactly 12 grams of pure 12C. c 1 Easy 3.2 general chemistry 102. A sample of dysprosium (atomic mass 162.5 u) contains 8 atoms. Determine the mass of the sample. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a 1 Moderate 3.2 general chemistry a. b. c. d. e. 2.16 × 10 1.08 × 10 −21 −21 g g 0.88 × 10−21 g −21 −21 3.65 × 10 4.11 × 10 g g 103. A sample of a content in the carbon dioxide obtained is 41.34% and the hydrogen content in the water obtained is 3.47%. Determine the empirical formula of the compound. Copyright Cengage Learning. Powered by Cognero. Page 33 compound containing hydrogen, carbon, and sulfur is reacted with oxygen. The carbon a. b. c. d. C4H2S2 C2H2S C3H2S CH4S2 Chapter 03 - Stoichiometry e. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: C2HS2 104. A white salt sample is analyzed and found to be made of potassium, oxygen, and carbon. It contains 56.58% of potassium and 34.73% of oxygen. The salt has a molar mass of 138.205 g. Compute the salt’s empirical and molecular formulas. a. b. c. d. e. ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: K3C2O2, K6C4O4 KC3O2, K2C6O4 K2C2O2, K2C2O2 K2CO3, K2CO3 KC2O3, K2C4O6 ANSWER: POINTS: DIFFICULTY: TOPICS: KEYWORDS: a 1 Difficult 3.6 general chemistry Copyright Cengage Learning. Powered by Cognero. Page 34 a. b. c. d. e. C10H14N2 C4H12N8 C6H8N4 C14H12N6 C10H8N3 b 1 Moderate 3.6 general chemistry d 1 Difficult 3.6 general chemistry 105. Nicotine is a stimulant drug that contains carbon, hydrogen, and nitrogen. The mass percent of carbon, hydrogen, and nitrogen in nicotine is 74.03%, 8.698%, and 17.267%, respectively. If the molar mass of nicotine is 162.23 g, determine its molecular formula.