© Copyright Pearson Prentice Hall Slide 1 of 41 The Arithmetic of Equations More than 3000 cocoons are needed to produce enough silk to make just one elegant Japanese kimono. Like silk manufacturers, chemists must know how much reactant they need to make a certain amount of product. Determining the quantities of reactants and products in a reaction requires a balanced chemical equation. 12.1

© Copyright Pearson Prentice Hall Slide 2 of 41 Using Everyday Equations How is a balanced equation like a recipe? 12.1

© Copyright Pearson Prentice Hall Slide 3 of 41 Using Everyday Equations A balanced chemical equation provides the same kind of quantitative information that a recipe does. 12.1

© Copyright Pearson Prentice Hall Slide 4 of 41 Using Everyday Equations An equation can represent the manufacturing of a single tricycle. 12.1

© Copyright Pearson Prentice Hall Slide 5 of 41

© Copyright Pearson Prentice Hall Slide 6 of 41 Interpreting a Balanced Equation

© Copyright Pearson Prentice Hall Chemical Calculations > Slide 7 of 41 Writing and Using Mole Ratios How are mole ratios used in chemical calculations? 12.2

© Copyright Pearson Prentice Hall Slide 8 of 41 Chemical Calculations > Writing and Using Mole Ratios In chemical calculations, mole ratios are used to convert between moles of reactant and moles of product, between moles of reactants, or between moles of products. 12.2

Slide 9 of 41 © Copyright Pearson Prentice Hall Chemical Calculations > Writing and Using Mole Ratios Mole-Mole Calculations A mole ratio is a conversion factor derived from the coefficients of a balanced chemical equation interpreted in terms of moles. 12.2

Slide 10 of 41 © Copyright Pearson Prentice Hall Chemical Calculations > Writing and Using Mole Ratios To determine the number of moles in a sample of a compound, first measure the mass of the sample. Then use the molar mass to calculate the number of moles in that mass. 12.2

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 11 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 12 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 13 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 14 of

© Copyright Pearson Prentice Hall Slide 15 of 41 Practice Problems for Sample Problem 12.2 Problem Solving Solve Problem 12 with the help of an interactive guided tutorial.

Slide 16 of 41 © Copyright Pearson Prentice Hall Chemical Calculations > Writing and Using Mole Ratios Mass-Mass Calculations 12.2

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 17 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 18 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 19 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 20 of

© Copyright Pearson Prentice Hall Slide 21 of 41 Practice Problems for Sample Problem 12.3 Problem Solving Solve Problem 13 with the help of an interactive guided tutorial. `

© Copyright Pearson Prentice Hall Chemical Calculations > Slide 22 of 41 Other Stoichiometric Calculations What is the general procedure for solving a stoichiometric problem? 12.2

Slide 23 of 41 © Copyright Pearson Prentice Hall Chemical Calculations > Other Stoichiometric Calculations In a typical stoichiometric problem, the given quantity is first converted to moles. Then the mole ratio from the balanced equation is used to calculate the number of moles of the wanted substance. Finally, the moles are converted to any other unit of measurement related to the unit mole, as the problem requires. 12.2

© Copyright Pearson Prentice Hall Slide 24 of 41 Chemical Calculations > Other Stoichiometric Calculations Solution Diagram 12.2

© Copyright Pearson Prentice Hall Slide 25 of 41 Chemical Calculations > Other Stoichiometric Calculations Problem-Solving Approach 12.2

© Copyright Pearson Prentice Hall Slide 26 of 41 Chemical Calculations > Other Stoichiometric Calculations Simulation 13 Strengthen your analytical skills by solving stoichiometric problems.

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 27 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 28 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 29 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 30 of

© Copyright Pearson Prentice Hall Slide 31 of 41 Practice Problems for Sample Problem 12.4 Problem Solving Solve Problem 15 with the help of an interactive guided tutorial.

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 32 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 33 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 34 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 35 of

© Copyright Pearson Prentice Hall Slide 36 of 41 Practice Problems for Sample Problem 12.5 Problem Solving Solve Problem 18 with the help of an interactive guided tutorial.

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 37 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 38 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 39 of

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 40 of

© Copyright Pearson Prentice Hall Slide 41 of 41 Practice Problems for Sample Problem 12.5 Problem-Solving Solve Problem 19 with the help of an interactive guided tutorial.

© Copyright Pearson Prentice Hall Slide 42 of 41 Section Quiz -or- Continue to: Launch: Assess students’ understanding of the concepts in Section 12.2 Section Quiz

© Copyright Pearson Prentice Hall Slide 43 of Section Quiz. 1.How many moles of water are produced when 2.5 mol of O 2 react according to the following equation? C 3 H 8 + 5O 2  3CO 2 + 4H 2 O a.2.0 b.2.5 c.3.0 d.4.0

© Copyright Pearson Prentice Hall Slide 44 of 41 2.Nitrogen gas reacts with hydrogen gas to produce ammonia gas. N 2 (g) + 3H 2 (g)  2NH 3 (g) What volume of H 2 is required to react with 3.00 L of N 2, and what volume of NH 3 is produced at 200°C? a.volume of H 2 = 9.00 L, volume of NH 3 = 6.00 L b.volume of H 2 = 3.00 L, volume of NH 3 = 3.00 L c.volume of H 2 = 3.00 L, volume of NH 3 = 6.00 L d.volume of H 2 = 1.00 L, volume of NH 3 = 1.50 L 12.2 Section Quiz

© Copyright Pearson Prentice Hall Slide 45 of 41 3.Automotive airbags inflate when sodium azide, NaN 3, rapidly decomposes to its component elements via this reaction: 2NaN 3  2Na + 3N 2. How many grams of sodium azide are required to form 5.00 g of nitrogen gas? a g b g c.7.74 g d.1.36 g 12.2 Section Quiz

END OF SHOW