1. Stoichiometry

2. Standard
Students know how to determine the molar mass of a molecule from its chemical formula and a table of atomic masses and how to convert the mass of a molecular substance to moles, number of particles, or volume of gas at standard temperature and pressure.
Students know how to calculate the masses of reactants and products in a chemical reaction from the mass of one of the reactants or products and the relevant atomic masses.

3. Turkey Sandwiches
2 Slices of Bread + 2 Slice of Cheese + 5 Slices Turkey  1 Turkey Sandwich
If I have 6 slices of bread, how many sandwiches can I
make?
How many slices of cheese and turkey will I need?
If I want to make 38 turkey sandwiches (one for each person in class), how many slices of bread, slices of cheese, and slices of turkey will I need?
How did you perform these calculations?

4. Chocolate Chip Cookies
This recipe yields 4 dozen cookies
1 cup of chocolate chips = 60 g
1 cup flour= 125 g
1 cup butter= 227 g
1 cup sugar= 220 g
1 cup butter, softened
1 cup white sugar
1 cup packed brown sugar
2 eggs
2 teaspoons vanilla extract
3 cups all-purpose flour

1 teaspoon baking soda
2 teaspoons hot water
1/2 teaspoon salt
2 cups semisweet chocolate chips
If you have 908 g of butter, how many cookies can you make?
How many grams of chocolate chips will you need?

5. Greek for “measuring elements”
Stoichiometry
Greek for “measuring elements”
Study of quantities of materials consumed and produced in chemical reactions.
Qualitative
Quantative

6. In terms of atoms and molecules:
2H2 + O2 ® 2H2O
Two molecules of hydrogen and one molecule of oxygen form two molecules of water.
2 Al2O3 ® 4Al + 3O2
2 molecules of aluminum oxide decompose to form 4 atoms of aluminum and 3 molecules of oxygen.

7. In terms of Moles
2H2 + O2 ® 2H2O
Two moles of hydrogen and one mole of oxygen form two moles of water.
2 Al2O3 ® 4Al + 3O2
2 moles of aluminum oxide decompose to form 4 moles of aluminum and 3 moles of oxygen.

8. 2H2 + O2 ® 2H2O 2 moles 1 mole 2 moles 4 moles ? ? 10 moles ? ?
In terms of Moles
2H O2 ® 2H2O
2 moles mole 2 moles
4 moles ? ?
10 moles ? ?
1 mole ? ?
? ? 3.0 moles
? moles ?

9. In terms of Unit Analysis:
2H2 + O2 ® 2H2O
How many moles of water could be produced by 2.00 mol of oxygen?
2.00 mol O mol H2O
1 mol O2
Ratio of coefficients
How many grams of water is that?

10. In terms of Unit Analysis:
2H2 + O2 ® 2H2O
How many moles of oxygen would be needed to produce 5.00 mol of water?
5.00 mol H2 O 1 mol O2
2 mol H2 O
How many grams of oxygen is that?
For every 2 moles of water produced, 1 mole of oxygen is needed

11. Solving Stoichiometry Problems
Write these steps on the left side of your notebook
Your “recipe” (chemical rxn) calls for moles.
If you are given the amount in grams or molecules, convert to moles.
You are asked to determine how much ingredients you need (reactants) or how much of something you will end up with you will make (products).
Use ratio of coefficients to find how much is needed.
If you are asked to find that amount in grams/molecules, convert moles to the unit you are asked to find.

12. Mole to mass conversions (Molar mass) and mole to molecules conversions (Avogadro’s #) will always have the same molecule/atom in the numerator and denominator
Ex mol Al2O3
102 g Al2O3
NOT 1 mol O2 This is like saying…
102 g Al2O dozen donuts
102 g eggs

13. Practice Unit Analysis: Mole-Mass
4Al + 3O2 ® 2Al2O3
How many grams of aluminum oxide could be produced by 4.00 mol of oxygen?
4.00 mol O mol Al2O3
3 mol O2
1 mol Al2O3
102 g Al2O3 =

14. Practice Unit Analysis: Mass-Mole
How many moles of chlorine are required to react completely with 69.0 grams of sodium to produce sodium chloride?
2 Na + Cl2  2 NaCl
69.0 g Na 1 mol Na
23 g Na
1 mol Cl2
2 mol Na
= 1.50 mol Cl2

15. Practice Unit Analysis: Mass-Mass
Calculate how many grams of ammonia are produced when you react 28.0g of nitrogen with excess hydrogen.
N2 + 3 H2  2 NH3

16. Stoichiometry Organizer
MASS
MASS
Molar Mass
Molar Mass
MOLES
MOLES
Ratio of
Coefficients
MOLECULES
MOLECULES
Avogadros #
Avogadros #
Molar Volume of Gas
Molar Volume of Gas
VOLUME
VOLUME

17. Quiz 11-27
N H2  2 NH3
How many moles of H2 would be needed to produce 1.8 mol of NH3?

18. Quiz 11-27a
N H2  2 NH3
How many moles of H2 would be needed to react with 3.0 mol of N2?

19. Quiz a
N H2  2 NH3
How many grams of NH3 could be produced by 1.0 mol of N2?

20. Quiz b
N H2  2 NH3
How many grams of NH3 could be produced by 3.0 mol of H2?

21. Quiz c
2 Na + Cl2  2 NaCl
How many moles of chlorine are required to react completely with 69.0 grams of sodium to produce sodium chloride?

22. Quiz d
4 Al + 3O2  2 Al2O3
How many grams of aluminum oxide could be produced by 27.0 g of aluminum?

23. Quiz 11-16
N H2  2 NH3
How many grams of NH3 could be produced by 15.0 g of H2?

24. Quiz a
N H2  2 NH3
How many grams of NH3 could be produced by 9.0 g of H2?

25. Quiz b
2 Na + Cl2  2 NaCl
How many grams of NaCl could be produced by 140 g of Cl2?

26. Quiz c
CH4 + 2 O2  CO2 + 2 H2O
How many grams of H2O could be produced by 64 g of CH4?

27. Quiz d
4 Fe + 3 O2  2 Fe2O3
How many grams of Fe2O3 could be produced by 112 g of Fe?

28. Quiz a
2 Mg + O2  2 MgO
How many grams of MgO could be produced by 96 g of O2?

29. Quiz b
WO3 + 3 H2  W + 3 H2O
How many grams of W could be produced by 6.0 g of H2?

30. Quiz 11-29
N H2  2 NH3
How many grams of NH3 could be produced by L of N2?

31. Quiz 12-17b
2 Na + Cl2  2 NaCl
How many grams of NaCl could be produced by 89.6 L of Cl2?

32. Quiz a
4 Al + 3O2  2 Al2O3
How many grams of aluminum oxide could be produced by 108 g of aluminum?

33. Quiz b
4 Al + 3O2  2 Al2O3
How many liters of oxygen would be needed to produce 34.0 g of aluminum oxide?