1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu How to Use This Presentation To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show.” To advance through the presentation, click the right-arrow key or the space bar. From the resources slide, click on any resource to see a presentation for that resource. From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation. You may exit the slide show at any time by pressing the Esc key.

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter Presentation Transparencies Lesson Starters Visual Concepts Resources Standardized Test Prep Sample Problems

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Table of Contents Stoichiometry Section 1 Introduction to Stoichiometry Section 2 Ideal Stoichiometric Calculations Section 3 Limiting Reactants and Percentage Yield

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Section 1 Introduction to Stoichiometry Lesson Starter Mg(s) + 2HCl(aq)  MgCl 2 (aq) + H 2 (g) If 2 mol of HCl react, how many moles of H 2 are obtained? How many moles of Mg will react with 2 mol of HCl? If 4 mol of HCl react, how many mol of each product are produced? How would you convert from moles of substances to masses?

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Section 1 Introduction to Stoichiometry Objective Define stoichiometry. Describe the importance of the mole ratio in stoichiometric calculations. Write a mole ratio relating two substances in a chemical equation.

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Section 1 Introduction to Stoichiometry Stoichiometry Definition Composition stoichiometry deals with the mass relationships of elements in compounds. Reaction stoichiometry involves the mass relationships between reactants and products in a chemical reaction.

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Visual Concepts Click below to watch the Visual Concept. Stoichiometry Visual Concept

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Problem Type 2: Given is an amount in moles and unknown is a mass Amount of given substance (mol) Problem Type 1: Given and unknown quantities are amounts in moles. Amount of given substance (mol) Reaction Stoichiometry Problems Section 1 Introduction to Stoichiometry Amount of unknown substance (mol) Mass of unknown substance (g) Amount of unknown substance (mol)

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Problem Type 4: Given is a mass and unknown is a mass. Mass of a given substance (g) Problem Type 3: Given is a mass and unknown is an amount in moles. Mass of given substance (g) Reaction Stoichiometry Problems, continued Section 1 Introduction to Stoichiometry Amount of unknown substance (mol) Amount of given substance (mol) Mass of unknown substance (g) Amount of unknown substance (mol) Amount of given substance (mol)

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Mole Ratio A mole ratio is a conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction Example: 2Al 2 O 3 (l)  4Al(s) + 3O 2 (g) Mole Ratios: 2 mol Al 2 O 3 2 mol Al 2 O 3 4 mol Al 4 mol Al 3 mol O 2 3 mol O 2,, Section 1 Introduction to Stoichiometry

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Converting Between Amounts in Moles Section 1 Introduction to Stoichiometry

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Stoichiometry Calculations Section 1 Introduction to Stoichiometry

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Visual Concepts Click below to watch the Visual Concept. Visual Concept Molar Mass as a Conversion Factor

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Lesson Starter Acid-Base Neutralization Reaction Demonstration What is the equation for the reaction of HCl with NaOH? What is the mole ratio of HCl to NaOH? Section 2 Ideal Stoichiometric Calculations

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Objective Calculate the amount in moles of a reactant or a product from the amount in moles of a different reactant or product. Calculate the mass of a reactant or a product from the amount in moles of a different reactant or product. Section 2 Ideal Stoichiometric Calculations

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Objectives, continued Calculate the amount in moles of a reactant or a product from the mass of a different reactant or product. Calculate the mass of a reactant or a product from the mass of a different reactant or product. Section 2 Ideal Stoichiometric Calculations

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Quantities in Moles Section 2 Ideal Stoichiometric Calculations

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Visual Concepts Click below to watch the Visual Concept. Visual Concept Conversion of Quantities in Moles

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Solving Mass-Mass Stoichiometry Problems Section 2 Ideal Stoichiometric Calculations

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Quantities in Moles, continued Sample Problem A In a spacecraft, the carbon dioxide exhaled by astronauts can be removed by its reaction with lithium hydroxide, LiOH, according to the following chemical equation. CO 2 (g) + 2LiOH(s)  Li 2 CO 3 (s) + H 2 O(l) How many moles of lithium hydroxide are required to react with 20 mol CO 2, the average amount exhaled by a person each day? Section 2 Ideal Stoichiometric Calculations

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Quantities in Moles, continued Sample Problem A Solution CO 2 (g) + 2LiOH(s)  Li 2 CO 3 (s) + H 2 O(l) Given: amount of CO 2 = 20 mol Unknown: amount of LiOH (mol) Solution: mol ratio Section 2 Ideal Stoichiometric Calculations

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Amounts in Moles to Mass Section 2 Ideal Stoichiometric Calculations

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Solving Stoichiometry Problems with Moles or Grams Section 2 Ideal Stoichiometric Calculations

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Amounts in Moles to Mass, continued Sample Problem B In photosynthesis, plants use energy from the sun to produce glucose, C 6 H 12 O 6, and oxygen from the reaction of carbon dioxide and water. What mass, in grams, of glucose is produced when 3.00 mol of water react with carbon dioxide? Section 2 Ideal Stoichiometric Calculations

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Amounts in Moles to Mass, continued Sample Problem B Solution Given: amount of H 2 O = 3.00 mol Unknown: mass of C 6 H 12 O 6 produced (g) Solution: Balanced Equation: 6CO 2 (g) + 6H 2 O(l)  C 6 H 12 O 6 (s) + 6O 2 (g) mol ratio molar mass factor 90.1 g C 6 H 12 O 6 Section 2 Ideal Stoichiometric Calculations

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Mass to Amounts in Moles Section 2 Ideal Stoichiometric Calculations

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Visual Concepts Click below to watch the Visual Concept. Visual Concept Mass and Number of Moles of an Unknown

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Mass to Amounts in Moles, continued Sample Problem D The first step in the industrial manufacture of nitric acid is the catalytic oxidation of ammonia. NH 3 (g) + O 2 (g)  NO(g) + H 2 O(g) (unbalanced) The reaction is run using 824 g NH 3 and excess oxygen. a. How many moles of NO are formed? b. How many moles of H 2 O are formed? Section 2 Ideal Stoichiometric Calculations

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Mass to Amounts in Moles, continued Sample Problem D Solution Given: mass of NH 3 = 824 g Unknown:a. amount of NO produced (mol) b. amount of H 2 O produced (mol) Solution: Balanced Equation: 4NH 3 (g) + 5O 2 (g)  4NO(g) + 6H 2 O(g) a. b. molar mass factor mol ratio Section 2 Ideal Stoichiometric Calculations

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Conversions of Mass to Amounts in Moles, continued Sample Problem D Solution, continued a. b. molar mass factor mol ratio Section 2 Ideal Stoichiometric Calculations

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Mass-Mass to Calculations Section 2 Ideal Stoichiometric Calculations

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Visual Concepts Click below to watch the Visual Concept. Visual Concept Mass-Mass Calculations

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Solving Mass-Mass Problems Section 2 Ideal Stoichiometric Calculations

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Mass-Mass to Calculations, continued Sample Problem E Tin(II) fluoride, SnF 2, is used in some toothpastes. It is made by the reaction of tin with hydrogen fluoride according to the following equation. Sn(s) + 2HF(g)  SnF 2 (s) + H 2 (g) How many grams of SnF 2 are produced from the reaction of 30.00 g HF with Sn? Section 2 Ideal Stoichiometric Calculations

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Mass-Mass to Calculations, continued Sample Problem E Solution Given: amount of HF = 30.00 g Unknown: mass of SnF 2 produced (g) Solution: molar mass factor mol ratio molar mass factor = 117.5 g SnF 2 Section 2 Ideal Stoichiometric Calculations

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Section 2 Ideal Stoichiometric Calculations Solving Various Types of Stoichiometry Problems

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Solving Various Types of Stoichiometry Problems Section 2 Ideal Stoichiometric Calculations

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Solving Volume-Volume Problems Section 2 Ideal Stoichiometric Calculations

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Solving Particle Problems Section 2 Ideal Stoichiometric Calculations

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Objectives Describe a method for determining which of two reactants is a limiting reactant. Calculate the amount in moles or mass in grams of a product, given the amounts in moles or masses in grams of two reactants, one of which is in excess. Distinguish between theoretical yield, actual yield, and percentage yield. Calculate percentage yield, given the actual yield and quantity of a reactant. Section 3 Limiting Reactants and Percentage Yield

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Limiting Reactants The limiting reactant is the reactant that limits the amount of the other reactant that can combine and the amount of product that can form in a chemical reaction. The excess reactant is the substance that is not used up completely in a reaction. Section 3 Limiting Reactants and Percentage Yield

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Visual Concepts Click below to watch the Visual Concept. Visual Concept Limiting Reactants and Excess Reactants

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Limited Reactants, continued Sample Problem F Silicon dioxide (quartz) is usually quite unreactive but reacts readily with hydrogen fluoride according to the following equation. SiO 2 (s) + 4HF(g)  SiF 4 (g) + 2H 2 O(l) If 6.0 mol HF is added to 4.5 mol SiO 2, which is the limiting reactant? Section 3 Limiting Reactants and Percentage Yield

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Limited Reactants, continued Sample Problem F Solution SiO 2 (s) + 4HF(g)  SiF 4 (g) + 2H 2 O(l) Given: amount of HF = 6.0 mol amount of SiO 2 = 4.5 mol Unknown: limiting reactant Solution: mole ratio Section 3 Limiting Reactants and Percentage Yield

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Limited Reactants, continued Sample Problem F Solution, continued SiO 2 (s) + 4HF(g)  SiF 4 (g) + 2H 2 O(l) Section 3 Limiting Reactants and Percentage Yield HF is the limiting reactant.

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Percentage Yield The theoretical yield is the maximum amount of product that can be produced from a given amount of reactant. The actual yield of a product is the measured amount of that product obtained from a reaction. The percentage yield is the ratio of the actual yield to the theoretical yield, multiplied by 100. Section 3 Limiting Reactants and Percentage Yield

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Visual Concepts Click below to watch the Visual Concept. Visual Concept Comparing Actual and Theoretical Yield

48. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Percentage Yield, continued Sample Problem H Chlorobenzene, C 6 H 5 Cl, is used in the production of many important chemicals, such as aspirin, dyes, and disinfectants. One industrial method of preparing chlorobenzene is to react benzene, C 6 H 6, with chlorine, as represented by the following equation. C 6 H 6 (l) + Cl 2 (g)  C 6 H 5 Cl(l) + HCl(g) When 36.8 g C 6 H 6 react with an excess of Cl 2, the actual yield of C 6 H 5 Cl is 38.8 g. What is the percentage yield of C 6 H 5 Cl? Section 3 Limiting Reactants and Percentage Yield

49. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Percentage Yield, continued Sample Problem H Solution C 6 H 6 (l) + Cl 2 (g)  C 6 H 5 Cl(l) + HCl(g) Given:mass of C 6 H 6 = 36.8 g mass of Cl 2 = excess actual yield of C 6 H 5 Cl = 38.8 g Unknown: percentage yield of C 6 H 5 Cl Solution: Theoretical yield molar mass factor mol ratio molar mass Section 3 Limiting Reactants and Percentage Yield

50. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Percentage Yield, continued Sample Problem H Solution, continued C 6 H 6 (l) + Cl 2 (g)  C 6 H 5 Cl(l) + HCl(g) Theoretical yield Section 3 Limiting Reactants and Percentage Yield Percentage yield

51. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu End of Chapter 9 Show

52. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 1.In stoichiometry, chemists are mainly concerned with A.the types of bonds found in compounds. B.mass relationships in chemical reactions. C.energy changes occurring in chemical reactions. D.the speed with which chemical reactions occur. Standardized Test Preparation

53. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 1.In stoichiometry, chemists are mainly concerned with A.the types of bonds found in compounds. B.mass relationships in chemical reactions. C.energy changes occurring in chemical reactions. D.the speed with which chemical reactions occur. Standardized Test Preparation

54. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 2. Assume ideal stoichiometry in the reaction CH 4 + 2O 2  CO 2 + 2H 2 O. If you know the mass of CH 4, you can calculate A.only the mass of CO 2 produced. B.only the mass of O 2 reacting. C.only the mass of CO 2 + H 2 O produced. D.the mass of O 2 reacting and CO 2 + H 2 O produced. Standardized Test Preparation Multiple Choice

55. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 2. Assume ideal stoichiometry in the reaction CH 4 + 2O 2  CO 2 + 2H 2 O. If you know the mass of CH 4, you can calculate A.only the mass of CO 2 produced. B.only the mass of O 2 reacting. C.only the mass of CO 2 + H 2 O produced. D.the mass of O 2 reacting and CO 2 + H 2 O produced. Standardized Test Preparation

56. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 3.Which mole ratio for the equation 6Li + N 2  2Li 3 N is incorrect? A. C. B. D. 6 mol Li 2 mol N 2 2 mol Li 3 N 1 mol N 2 6 mol Li 2 mol Li 3 N 6 mol Li Standardized Test Preparation

57. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 3.Which mole ratio for the equation 6Li + N 2  2Li 3 N is incorrect? A. C. B. D. 6 mol Li 2 mol N 2 2 mol Li 3 N 1 mol N 2 6 mol Li 2 mol Li 3 N 6 mol Li Standardized Test Preparation

58. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 4. For the reaction below, how many moles of N 2 are required to produce 18 mol NH 3 ? N 2 + 3H 2  2NH 3 A. 4.5 B. 9.0 C. 18 D. 36 Standardized Test Preparation

59. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 4.For the reaction below, how many moles of N 2 are required to produce 18 mol NH 3 ? N 2 + 3H 2  2NH 3 A. 4.5 B. 9.0 C. 18 D. 36 Standardized Test Preparation

60. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 5.What mass of NaCl can be produced by the reaction of 0.75 mol Cl 2 ? 2Na + Cl 2  2NaCl A. 0.75 g B. 1.5 g C. 44 g D. 88 g Standardized Test Preparation

61. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 5.What mass of NaCl can be produced by the reaction of 0.75 mol Cl 2 ? 2Na + Cl 2  2NaCl A. 0.75 g B. 1.5 g C. 44 g D. 88 g Standardized Test Preparation

62. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 6. What mass of CO 2 can be produced from 25.0 g CaCO 3 given the decomposition reaction CaCO 3  CaO + CO 2 A. 11.0 g B. 22.0 g C. 25.0 g D. 56.0 g Standardized Test Preparation

63. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 6. What mass of CO 2 can be produced from 25.0 g CaCO 3 given the decomposition reaction CaCO 3  CaO + CO 2 A. 11.0 g B. 22.0 g C. 25.0 g D. 56.0 g Standardized Test Preparation

64. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 7. If a chemical reaction involving substances A and B stops when B is completely used up, then B is referred to as the A. excess reactant. B. primary reactant. C. limiting reactant. D. primary product. Standardized Test Preparation

65. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 7. If a chemical reaction involving substances A and B stops when B is completely used up, then B is referred to as the A. excess reactant. B. primary reactant. C. limiting reactant. D. primary product. Standardized Test Preparation

66. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 8.If a chemist calculates the maximum amount of product that could be obtained in a chemical reaction, he or she is calculating the A. percentage yield. B. mole ratio. C. theoretical yield. D. actual yield. Standardized Test Preparation

67. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 8.If a chemist calculates the maximum amount of product that could be obtained in a chemical reaction, he or she is calculating the A. percentage yield. B. mole ratio. C. theoretical yield. D. actual yield. Standardized Test Preparation

68. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 9. What is the maximum number of moles of AlCl 3 that can be produced from 5.0 mol Al and 6.0 mol Cl 2 ? 2Al + 3Cl 2  2AlCl 3 A. 2.0 mol AlCl 3 B. 4.0 mol AlCl 3 C. 5.0 mol AlCl 3 D. 6.0 mol AlCl 3 Standardized Test Preparation

69. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Multiple Choice 9. What is the maximum number of moles of AlCl 3 that can be produced from 5.0 mol Al and 6.0 mol Cl 2 ? 2Al + 3Cl 2  2AlCl 3 A. 2.0 mol AlCl 3 B. 4.0 mol AlCl 3 C. 5.0 mol AlCl 3 D. 6.0 mol AlCl 3 Standardized Test Preparation

70. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Short Answer 10.Why is a balanced equation necessary to solve a mass-mass stoichiometry problem? Standardized Test Preparation

71. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Short Answer 10.Why is a balanced equation necessary to solve a mass-mass stoichiometry problem? Answer: The coefficients of the balanced equation are needed for the mole-mole ratio that is necessary to solve stoichiometric problems involving two different substances. Standardized Test Preparation

72. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Short Answer Standardized Test Preparation 11.What data are necessary to calculate the percentage yield of a reaction?

73. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Short Answer 11.What data are necessary to calculate the percentage yield of a reaction? Answer: the theoretical yield and the actual yield of the product Standardized Test Preparation

74. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Extended Response 12.A student makes a compound in the laboratory and reports an actual yield of 120%. Is this result possible? Assuming that all masses were measured correctly, give an explanation. Standardized Test Preparation

75. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Extended Response 12.A student makes a compound in the laboratory and reports an actual yield of 120%. Is this result possible? Assuming that all masses were measured correctly, give an explanation. Answer: The product was impure, so the mass contained the product and other substances. For example, if NaCl is made from HCl and NaOH but is not dried, the mass of NaCl can include water, which would result in a yield greater than 100%. Standardized Test Preparation

76. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Extended Response 13. Benzene, C 6 H 6, is reacted with bromine, Br 2, to produce bromobenzene, C 6 H 5 Br, and hydrogen bromide, HBr, as shown below. When 40.0 g of benzene are reacted with 95.0 g of bromine, 65.0 g of bromobenzene is produced. C 6 H 6 + Br 2  C 6 H 5 Br + HBr a.Which compound is the limiting reactant? b.What is the theoretical yield of bromobenzene? c.What is the reactant in excess, and how much remains after the reaction is completed? d.What is the percentage yield? Standardized Test Preparation

77. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 9 Extended Response 13. Benzene, C 6 H 6, is reacted with bromine, Br 2, to produce bromobenzene, C 6 H 5 Br, and hydrogen bromide, HBr, as shown below. When 40.0 g of benzene are reacted with 95.0 g of bromine, 65.0 g of bromobenzene is produced. C 6 H 6 + Br 2  C 6 H 5 Br + HBr a.Which compound is the limiting reactant? benzene b.What is the theoretical yield of bromobenzene? 80.4 g c.What is the reactant in excess, and how much remains after the reaction is completed? bromine, 13.2 g d.What is the percentage yield? 80.8% Standardized Test Preparation