Chapter 9 - Stoichiometry 9.1 The Arithmetic of Equations 9.2 Chemical Calculations 9.3 Limiting Reagent and Percent Yield

9.1 The Arithmetic of Equations Using Everyday Equations Building a bicycle (Figure 9.2) Baking brownies! Interpreting Chemical Equations

9.2 Chemical Calculations Mole-Mole Calculations The Mole Ratio: N2 (g) + 3H2 (g) = 2NH3 (g) is the formation of ammonia. Using the coefficients as mole amounts we can set up “ratios” of equivalent substances (conservation of mass) – the mole ratio. 1 mol N2 / 3 mol H2 3 mol H2 / 2 mol NH3 2 mol NH3 / 1 mol N2 These are used to solve problems involving substance amounts and balanced chemical equations.

Chapter 9 Assignments CPQ # 1 pp.262–63 # 33,34,36,37,38,39,41

9.3 Limiting Reagent and Percent Yield What is a Limiting Reagent? Back to some Limiting versus excess “common” examples… Problems…

9.3 Limiting Reagent and Percent Yield (cont.) 100%! Batting averages, grades, etc. % yield = actual yield / theoretical yield x 100 Ex: 50 g NaCl / 75 g NaCl x 100 = 66.6% Need to know the actual and theoretical yields!

Chapter 9 Assignments CPQ # 1 pp.262–63 # 33,34,36,37,38,39,41 # 42-47,49