1. Unit 7: Stoichiometry
Chapter 12.1
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2. Stoichiometry Stoichiometry Greek for “measuring elements”
Pronounced “stoy kee ahm uh tree”
Definition:
Calculations of the quantities in chemical reactions, based on a balanced equation.

3. Stoichiometry
There are 4 ways to interpret a balanced chemical equation
Moles
Coefficient ratios
Particles
6.02 × 1023 particles/mole
Mass
Molar mass/mole
Volume
22.4 L/mole

4. Stoichiometry
Mass and atoms are ALWAYS conserved, however, molecules, formula units, moles, and volumes will not necessarily be conserved

5. Stoichiometry Mole to Mole Conversions
The coefficients tell us how many moles of each substance
2Al2O3 ® 4Al + 3O2
Molar Ratios
Each time we use 2 moles of Al2O3 we also make 3 moles of O2.
2 moles Al2O3
3 mole O2 or

6. Stoichiometry 2Al2O3 ® 4Al + 3O2 Mole to Mole Conversions Practice
How many moles of O2 are produced when 3.34 moles of Al2O3 decompose?
2Al2O3 ® 4Al + 3O2
3.34 mol Al2O3
2 mol Al2O3
3 mol O2 =
5.01 mol O2

7. Stoichiometry __Na + __H2O ® __NaOH + __H2 Mole to Mole Conversions
Practice
How many moles of H2 are produced when 2.05 moles of Na react with water?
__Na + __H2O ® __NaOH + __H2
2.05 mol Na
2 mol Na
1 mol H2 =
1.03 mol H2