1. Stoichiometric Calculations
Foldable

2. Foldable Obtain 3 sheets of paper.
Stagger the pages about ¾ of an inch.
Fold over so you have multiple flaps.

3. Titles of Pages Stoichiometric Calculations Mole to Mole
Mole to Mass / Mass to Mole
Mass to Mass
Limiting Reactant
Percent Yield

4. Page 1 - Top Open your book, on the top flap, write the following:
Steps in all stoichiometric calculations:
Write a balanced equation
Identify the known and unknown, what do you have and what are you trying to find?
Set up the problem with the given information
Identify the mole ratio
Check your answer, does it make sense?

5. Page 1 – Bottom – Mole to Mole
Mole of A to Mole of B
Ex. How many moles of H2O are produced from 5.0 moles of H2?
Balanced Eq: 2H2 + O2  2H2O
Known: 5.0 mol H2, Unknown: mols of H2O
= 5.00 mol H2O
5.0 mol H2
2 mol H2O
2 mol H2
Mole Ratio

6. Page 2- Bottom – Mass to Mole
Mole of A to Mass of B
Mass of A to Mole of B
How many grams of NaCl are produced from 5 moles of Na?
Balanced Eq: 2 Na + Cl2  2 NaCl
Known: 5 moles of Na
Unknown: grams of NaCl
How many moles of NaCl are produced from 35 g of Cl2?
Balanced Eq: 2 Na + Cl2  2 NaCl
Known: 35 g Cl2
Unknown: moles NaCl
5 mol Na
2 mol NaCl
58.44 g NaCl
35 g Cl2
1 mole Cl2
2 mol NaCl
2 mol Na
1 mol NaCl
70.90 g Cl2
1 mole Cl2
Mole Ratio
= 0.99 mol NaCl
= g NaCl

7. Page 3 – Bottom- Mass to Mass
Mass of A to Mass of B
Ex. How many grams of NO2 are produced from 250 g of N2 gas?
Balanced Eq: N2 + 2O2  2NO2
Known: 250 g of N2
Unknown: grams of NO2
= g NO2
46.01 g NO2
250 g N2
1 mol N2
2 mol NO2
28.02 g N2
1 mol N2
1 mol NO2
Molar Mass
Mole Ratio

8. Page 4 – Bottom – Limiting Reactants Same as all the other problems, you just have to do two of them.
If you have 25 g of N2 and 35 g of O2, how many grams of NO2 is produced, which one is the limiting reactant? The excess reactant?
Do the problem with N2 first.
Balanced Eq: N2 + 2O2  2NO2
Known: 25 g N2, Unknown: g NO2
= g NO2
Now do the same problem with O2
Same balanced equation
Known: 35 g O2 ,Unknown: g of NO2
= g NO2
25 g N2
1 mol N2
2 mol NO2
46.01 g NO2
35 g O2
1 mol O2
2 mol NO2
46.01 NO2
28.02 g N2
1 mol N2
1 mol NO2
32.00 g O2
2 mol O2
1 mol NO2
50.32 g NO2 is produced
NO2 is the excess reactant, it will be left over after the reaction.
O2 is the limiting reactant, this reactant will determine how much product is made.

9. Page 5 – Bottom - % Yield
Done the same way if you need to figure out the amount of product use the limiting reactant steps.
We will use the same balanced equation: N2 + 2O2  2NO2
We know that g NO2 is produced.
The amount of product you calculate from the limiting reactant problem is the theoretical yield.
50.32 g NO2 = theoretical yield
Ex. Problem: When this experiment was performed in the lab, the chemist was able to produce g of NO2.
48.45 g NO2 = actual yield
%Yield = actual yield
X 100
theoretical yield
% Yield =
X 100
50.32
= 96.3 %