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 Image and Math Focus Bank Bellringers Standardized Test Prep Visual Concepts Resources

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Reactions Table of Contents Section 1 Forming New Substances Section 2 Chemical Formulas and Equations Section 3 Types of Chemical Reactions Section 4 Energy and Rates of Chemical Reactions Chapter 14

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bellringer What do baking bread, launching the space shuttle, and digesting food have in common? Write your answer in your science journal. Chapter 14 Section 1 Forming New Substances

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Describe how chemical reactions produce new substances that have different chemical and physical properties. Identify four signs that indicate that a chemical reaction might be taking place. Explain what happens to chemical bonds during a chemical reaction. Chapter 14 Section 1 Forming New Substances

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Reactions A chemical reaction is a process in which one or more substances change to make one or more new substances. The chemical and physical properties of the new substances differ from those of the original substances. Chapter 14 Section 1 Forming New Substances

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Reactions, continued Signs of Chemical Reactions include color changes, gas formation, the formation of a precipitate (a solid substance formed in a solution), and energy given off as light, thermal energy, or electrical energy. A Change of Properties The most important sign of a chemical reaction is the formation of new substances that have different properties. Chapter 14 Section 1 Forming New Substances

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bonds: Holding Molecules Together A chemical bond is an attraction that holds atoms together in a molecule. Breaking and Making Bonds If molecules bump into each other with enough energy, the chemical bonds in the molecules break. The atoms then rearrange, and new bonds form to make new substances. Chapter 14 Section 1 Forming New Substances

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Section 1 Forming New Substances

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bonds: Holding Molecules Together, continued New Bonds, New Substances Whenever new substances form, their properties differ from the properties of the starting substances. For example, sodium is a violently reactive metal and chlorine is a greenish poisonous gas. The two elements combine to form a white solid called sodium chloride, or table salt. Chapter 14 Section 1 Forming New Substances

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bellringer Write the following chemical symbols in your science journal. Then, try to write the names of the elements matching the symbols. HOCNaNClK MgCaAlAuFCuFe Chapter 14 Section 2 Chemical Formulas and Equations

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Interpret and write simple chemical formulas. Write and balance simple chemical equations. Explain how a balanced equation shows the law of conservation of mass. Chapter 14 Section 2 Chemical Formulas and Equations

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Formulas A chemical formula is a combination of chemical symbols and numbers to represent a substance. A chemical formula shows how many atoms of each kind are present in a molecule. Chapter 14 Section 2 Chemical Formulas and Equations

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Formula Chapter 14 Section 2 Chemical Formulas and Equations Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Formulas, continued Writing Formulas for Covalent Compounds You can use the name of a covalent compound to write its chemical formula. The names of covalent compounds use prefixes. Each prefix represents a number, as shown below. Chapter 14 Section 2 Chemical Formulas and Equations mono-1hexa-6 di-2hepta-7 tri-3octa-8 tetra-4nona-9 penta-5deca-10

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Formulas, continued Writing Formulas for Ionic Compounds To write the formula for an ionic compound, make sure the compound’s charge is 0. The formula must have subscripts that cause the charges of the ions to cancel out. Chapter 14 Section 2 Chemical Formulas and Equations

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Section 2 Chemical Formulas and Equations

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Equations Describing Reactions by Using Equations A chemical equation uses chemical symbols and formulas as a shortcut to describe a chemical reaction. From Reactants to Products The starting materials in a reaction are reactants. The substances formed from a reaction are products. Chapter 14 Section 2 Chemical Formulas and Equations

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Section 2 Chemical Formulas and Equations

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Equations, continued The Importance of Accuracy The symbol or formula for each substance in a chemical equation must be written correctly or it will not correctly describe the reaction. Some formulas and symbols can be confused. Chapter 14 Section 2 Chemical Formulas and Equations

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Equations, continued The Reason Equations Must Be Balanced Atoms are never lost or gained in a chemical reaction, they are just rearranged. Every atom in the reactants becomes part of the products. When writing a chemical equation, make sure the number of atoms of each element in the reactants equals the number of atoms of those same elements in the products. This is called balancing the equation. Chapter 14 Section 2 Chemical Formulas and Equations

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Equations, continued In the 1700s, French chemist Antoine Lavoisier found that the total mass of the reactants was always the same as the total mass of the products. Lavoisier’s work led to the law of conservation of mass, which states that mass is neither created nor destroyed in ordinary chemical and physical changes. Chapter 14 Section 2 Chemical Formulas and Equations

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Equations, continued How to Balance an Equation To balance an equation, you must use coefficients. A coefficient is a number that is placed in front of a chemical symbol or formula. For an equation to be balanced, all atoms must be counted. So, you multiply the subscript of each element in a formula by the formula’s coefficient. The next slide shows how to use coefficients to balance an equation. Chapter 14 Section 2 Chemical Formulas and Equations

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Section 2 Chemical Formulas and Equations

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bellringer Are the products of a reaction always more complex than the reactants? Could products be simpler than the reactants? Explain your answers. Write your responses in your science journal. Chapter 14 Section 3 Types of Chemical Reactions

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Describe four types of chemical reactions. Classify a chemical equation as one of four types of chemical reactions. Chapter 14 Section 3 Types of Chemical Reactions

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Synthesis Reactions A synthesis reaction is a reaction in which two or more substances combine to form one new compound. For example, a synthesis reaction takes place when sodium reacts with chlorine to produce sodium chloride, which you know as table salt. Chapter 14 Section 3 Types of Chemical Reactions

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Decomposition Reactions A decomposition reaction is a reaction in which a single compound breaks down to form two or more simpler substances. Decomposition is the reverse of synthesis. Chapter 14 Section 3 Types of Chemical Reactions

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Single-Displacement Reactions A single-displacement reaction is a reaction in which an element replaces another element that is part of a compound. The products of single-displacement reactions are a new compound and a different element. Reactivity of Elements In a single-displacement reaction, a more reactive element can displace a less reactive element in a compound. Chapter 14 Section 3 Types of Chemical Reactions

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Double-Displacement Reactions A double-displacement reaction is a reaction in which ions from two compounds exchange places. One of the products of this type of reaction is often a gas or a precipitate. The next slide shows models of each of the four types of chemical reactions. Chapter 14 Section 3 Types of Chemical Reactions

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Section 3 Types of Chemical Reactions

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bellringer Now that you know a little about chemical reactions, think about the many chemical reactions that take place around you every day. Describe your favorite chemical reaction. How do you think energy is involved in the reaction? Write your answer in your science journal. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Compare exothermic and endothermic reactions. Explain activation energy. Interpret an energy diagram. Describe five factors that affect the rate of a reaction. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reactions and Energy By comparing the chemical energy of the reactants with the chemical energy of the products, you can decide if energy is released or absorbed in the reaction. Exothermic Reactions are reactions in which energy is released. Energy can be released as light, electrical energy, or thermal energy. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reactions and Energy, continued Endothermic Reactions are reactions in which energy is taken in. The Law of Conservation of Energy states that energy cannot be created or destroyed. The energy released in exothermic reactions was first stored in the chemical bonds of the reactants. And the energy taken in during endothermic reactions is stored in the products. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Rates of Reactions The speed at which new particles form is called the rate of a reaction. Activation Energy is the smallest amount of energy that molecules need to react. A chemical reaction needs a boost of energy greater than or equal to the activation energy before the reaction can start. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Rates of Reactions, continued Sources of Activation Energy Friction is one source of activation energy. In a match, friction provides the energy needed to break the bonds in the reactants and allow new bonds to form. An electric spark in a car’s engine is another source of activation energy. This spark begins the burning of gasoline. Light can also be a source of activation energy for a reaction. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Activation Energy and Chemical Reactions Chapter 14 Section 4 Energy and Rates of Chemical Reactions Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Factors Affecting Rates of Reactions Temperature A higher temperature causes a faster rate of reaction. At high temperatures, particles of reactants move quickly and collide hard and often. At low temperatures, particles move slowly and collide less often. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Factors Affecting Rates of Reactions, continued Concentration In general, a high concentration of reactants causes a fast rate of reaction. Concentration is a measure of the amount of one substance when it is dissolved in another substance. When concentration is high, there are many reactant particles in a given volume. So, there is little distance between particles and the particles collide more often and react faster. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Factors Affecting Rates of Reactions, continued Surface Area is the amount of exposed surface of a substance. Increasing the surface area of solid reactants increases the rate of a reaction. Inhibitors are substances that slow down or stop a chemical reaction. The rate of a reaction decreases in the presence of an inhibitor. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Factors Affecting Rates of Reactions, continued Catalysts are substances that speed up a reaction without being permanently changed. Because it is not changed, a catalyst is not a reactant. A catalyst lowers the activation energy of a reaction, which allows the reaction to happen more quickly. Catalysts called enzymes speed up most reactions in your body. Chapter 14 Section 4 Energy and Rates of Chemical Reactions

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Concept Map Chapter 14 Chemical Reactions Use the terms below to complete the concept map on the next slide. products reactants chemical equations coefficients chemical reactions chemical formulas

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Chemical Reactions

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Chemical Reactions

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu End of Chapter 14 Show

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Read each of the passages. Then answer the questions that follow each passage. Chapter 14 Standardized Test Preparation

48. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 1 The key to an air bag’s success during a crash is the speed at which it inflates. Inside the bag is a gas generator that contains the compounds sodium azide, potassium nitrate, and silicon dioxide. At the moment of a crash, an electronic sensor in the car detects the sudden change in speed. The sensor sends a small electric current to the gas generator. Continued on the next slide Chapter 14 Standardized Test Preparation

49. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 1, continued This electric current provides the activation energy for the chemicals in the gas generator. The rate at which the reaction happens is very fast. In 1/25 of a second, the gas formed in the reaction inflates the bag. The air bag fills upward and outward. By filling the space between a person and the car’s dashboard, the air bag protects him or her from getting hurt. Chapter 14 Standardized Test Preparation

50. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which of the following events happens first? A The sensor sends an electric current to the gas generator. B The air bag inflates. C The air bag fills the space between the person and the dashboard. D The sensor detects a change in speed. Chapter 14 Standardized Test Preparation

51. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which of the following events happens first? A The sensor sends an electric current to the gas generator. B The air bag inflates. C The air bag fills the space between the person and the dashboard. D The sensor detects a change in speed. Chapter 14 Standardized Test Preparation

52. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. What provides the activation energy for the reaction to occur? F the speed of the car G the inflation of the air bag H the hot engine I the electric current from the sensor Chapter 14 Standardized Test Preparation

53. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. What provides the activation energy for the reaction to occur? F the speed of the car G the inflation of the air bag H the hot engine I the electric current from the sensor Chapter 14 Standardized Test Preparation

54. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. What is the purpose of this passage? A to convince the reader to wear a seat belt B to describe the series of events that inflate an air bag C to explain why air bags are an important safety feature in cars D to show how chemical reactions protect pedestrians Chapter 14 Standardized Test Preparation

55. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. What is the purpose of this passage? A to convince the reader to wear a seat belt B to describe the series of events that inflate an air bag C to explain why air bags are an important safety feature in cars D to show how chemical reactions protect pedestrians Chapter 14 Standardized Test Preparation

56. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 2 An important tool in fighting forest fires is a slimy, red goop. This mixture of powder and water is a very powerful fire retardant. The burning of trees, grass, and brush is an exothermic reaction. The fire retardant slows or stops this self-feeding reaction by increasing the activation energy for the materials to which it sticks. Continued on the next slide Chapter 14 Standardized Test Preparation

57. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 2, continued A plane can carry between 4,500 and 11,000 L of the goop. The plane then drops it all in front of the raging flames of a forest fire when the pilot presses the button. Firefighters on the ground can gain valuable time when a fire is slowed with a fire retardant. This extra time allows the ground team to create a fire line that will finally stop the fire. Chapter 14 Standardized Test Preparation

58. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which of the following sentences best summarizes the passage? A The burning of forests and other brush is an exothermic reaction. B Dropping fire retardants ahead of a flame can help firefighters on the ground stop a fire. C Firefighters on the ground create a fire line that will help stop the fire from spreading. D The slimy, red goop used as a fire retardant is made of a mixture of powder and water. Chapter 14 Standardized Test Preparation

59. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which of the following sentences best summarizes the passage? A The burning of forests and other brush is an exothermic reaction. B Dropping fire retardants ahead of a flame can help firefighters on the ground stop a fire. C Firefighters on the ground create a fire line that will help stop the fire from spreading. D The slimy, red goop used as a fire retardant is made of a mixture of powder and water. Chapter 14 Standardized Test Preparation

60. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Based on the passage, which of the following statements is a fact? F Fire retardants are always successful in putting out fires. G No more than 4,500 L of red goop are loaded onto a plane. H A fire retardant works by increasing the activation energy for the materials that it sticks on. I The burning of trees is an endothermic reaction. Chapter 14 Standardized Test Preparation

61. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Based on the passage, which of the following statements is a fact? F Fire retardants are always successful in putting out fires. G No more than 4,500 L of red goop are loaded onto a plane. H A fire retardant works by increasing the activation energy for the materials that it sticks on. I The burning of trees is an endothermic reaction. Chapter 14 Standardized Test Preparation

62. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics Use the energy diagram below to answer the questions that follow. Chapter 14 Standardized Test Preparation

63. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which letter represents the energy of the products? A B C D Chapter 14 Standardized Test Preparation

64. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which letter represents the energy of the products? A B C D Chapter 14 Standardized Test Preparation

65. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Which letter represents the activation energy of the reaction? F A G B H C I D Chapter 14 Standardized Test Preparation

66. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Which letter represents the activation energy of the reaction? F A G B H C I D Chapter 14 Standardized Test Preparation

67. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Which of the following statements best describes the reaction represented by the graph? A The reaction is endothermic because the energy of the products is greater than the energy of the reactants. B The reaction is endothermic because the energy of the reactants is greater than the energy of the products. C The reaction is exothermic because the energy of the products is greater than the energy of the reactants. D The reaction is exothermic because the energy of the reactants is greater than the energy of the products. Chapter 14 Standardized Test Preparation

68. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Which of the following statements best describes the reaction represented by the graph? A The reaction is endothermic because the energy of the products is greater than the energy of the reactants. B The reaction is endothermic because the energy of the reactants is greater than the energy of the products. C The reaction is exothermic because the energy of the products is greater than the energy of the reactants. D The reaction is exothermic because the energy of the reactants is greater than the energy of the products. Chapter 14 Standardized Test Preparation

69. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Math Read each question and choose the best answer. Chapter 14 Standardized Test Preparation

70. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Nina has 15 pens in her backpack. She has 3 red pens, 10 black pens, and 2 blue pens. If Ben selects a pen to borrow at random, what is the probability that the pen selected is red? A 2/15 B 1/5 C 1/3 D 2/3 Chapter 14 Standardized Test Preparation

71. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Nina has 15 pens in her backpack. She has 3 red pens, 10 black pens, and 2 blue pens. If Ben selects a pen to borrow at random, what is the probability that the pen selected is red? A 2/15 B 1/5 C 1/3 D 2/3 Chapter 14 Standardized Test Preparation

72. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. How many atoms of nitrogen, N, are in the formula for calcium nitrate, Ca(NO 3 ) 2 ? F 3 G 2 H 6 I 1 Chapter 14 Standardized Test Preparation

73. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. How many atoms of nitrogen, N, are in the formula for calcium nitrate, Ca(NO 3 ) 2 ? F 3 G 2 H 6 I 1 Chapter 14 Standardized Test Preparation

74. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Which letter best represents the number 2 3/5 on the number line? A P B Q C R D S Chapter 14 Standardized Test Preparation 0321 SRQP

75. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Which letter best represents the number 2 3/5 on the number line? A P B Q C R D S Chapter 14 Standardized Test Preparation 0321 SRQP

76. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 4. According to the following chemical equation, how many reactants are needed to form water and carbon dioxide? H 2 CO 3  H 2 O + CO 2 F one G two H three I four Chapter 14 Standardized Test Preparation

77. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 4. According to the following chemical equation, how many reactants are needed to form water and carbon dioxide? H 2 CO 3  H 2 O + CO 2 F one G two H three I four Chapter 14 Standardized Test Preparation

78. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Section 2 Chemical Formulas and Equations

79. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 14 Section 2 Chemical Formulas and Equations