1. Putting it all together
Stoichiometry

2. Lesson Essential Question
How can the mass of products be determined from the amounts of the reactants in a chemical reaction?

3. STOICHIOMETRY -
The study of quantities of materials consumed and produced in chemical reactions.

4. Mass-Mass Stoichiometry
If 20.0 grams of zinc pellets reacts with excess hydrochloric acid, how many grams of zinc chloride are going to be produced?
Zn(s) HCl(aq)  ZnCl2(aq) + H2(g) 1
1. Write a balanced equation. 1
20.0 g
excess
? grams
65.39 g/mole
g/mole
Write the “given” information from the problem under the corresponding chemical compound
Write down any information necessary to
change the given measurements to moles. (i.e. molar mass or molar volume at STP.)
20.0 g Zn 1
1 mole Zn
1 mole ZnCl2
g ZnCl2 = X X X
65.39 g Zn
1 mole Zn
1 mole ZnCl2
6. “Stoichiometry” Step. This step allows you to go from one compound to another “legally”. Only use the coefficients in front of the compounds involved in the problem
Using the information under your “given” and
convert grams to moles.
41.7 g ZnCl2 solid
4. Start the problem with your “given” over one.
7. Convert moles to appropriate answer unit
and use the calculator to solve the problem.

5. Mass-Mass Stoichiometry
6.50 grams of aluminum foil reacts with excess oxygen, how many grams of aluminum oxide are going to be produced?
4 Al(s) + 3 O2(g)  Al2O3(s)
1. Write a balanced equation.
6.50 g
excess
? grams
26.98 g/mole
g/mole
Write the “given” information from the problem under the corresponding chemical compound
Write down any information necessary to
change the given measurements to moles. (i.e. molar mass or molar volume at STP.)
6.50 g Al 1
1 mole Al
2 mole Al2O3
g Al2O3 = X X X
12.3 g Al2O3 solid
26.98 g Al
4 mole Al
1 mole Al2O3
Using the information under your “given” and
convert grams to moles.
Convert moles to the appropriate unit using
gathered information, Calculate answer.
6. “Stoichiometry” Step. This step allows you to go from one compound to another “legally”. Only use the coefficients in front of the compounds involved in the problem
4. Start the problem with your “given” over one.

6. Mass-Volume Stoichiometry
How many liters of oxygen gas, at STP can be collected from the complete decomposition of 50.0 g of potassium chlorate
2 KClO3(s)  KCl(s) O2(g)
1. Write a balanced equation.
50.0 g
? Liters at STP
g/mole
22.4 L/mole
Write down any information necessary to
change the given measurements to moles. (i.e. molar mass or molar volume at STP.)
Write the “given” information from the problem under the corresponding chemical compound
50.0 g KClO3 1
1 mole KClO3
3 mole O2
22.4 L O2 = X X X
g KClO3
2 mole KClO3
1 mole O2
13.71 L O2 gas
6. “Stoichiometry” Step. This step allows you to go from one compound to another “legally”. Only use the coefficients in front of the compounds involved in the problem
4. Start the problem with your “given” over one.
Using the information under your “given” and
convert grams to moles.
Convert moles to the appropriate unit using
gathered information, Calculate answer.