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

2. 9.1 The Arithmetic of Equations
Using Everyday Equations
Building a bicycle (Figure 9.2)
Baking brownies!
Interpreting Chemical Equations

3. 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.

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

7. 9.3 Limiting Reagent and Percent Yield
What is a Limiting Reagent?
Back to some Limiting versus excess “common” examples…
Problems…

9. 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!

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