Stoichiometry Unit Worksheet #9: Percent Yield
percentage yield = actual amount of product X 100 (Calculation is just like calculating your % on a quiz)
expected amount of product
Example 1: A student conducts a reaction that produces 2.755 grams of copper. Mathematically he
determines that 3.150 grams of copper should have been produced. Calculate the student's % yield.
Answer: actual amount of product
X 100 = 2.755 g X100 = 87.5%
expected amount of product
3.150 g
1.
In the reaction shown below, a student produces 22 grams of water. Mathematically he determines that 29
grams of water should have been produced. Calculate the student's percentage yield.
2H2 + O2 
synthesis
2.
The actual amount of MgO synthesized in the reaction shown below was 0.77 g. If the theoretical amount of
MgO was calculated to be 1.30 g, what is the percent yield of the reaction?
2Mg + O2 
synthesis
3.
A chemist starts with 11.2 g of KClO3 and calculates that it should be possible to make 7.6 g of KCl with that
much KClO3. After having conducted the reaction, she finds that she recovered only 6.8 g of KCl. What is her percent
yield?
2KClO3 
Decomposition (oxygen is one of the 2 products)
4.
You have 6.2 g of NH3 in the cabinet. You do a short calculation and figure out that this much NH3 will yield
0.92 g of H2 in the reaction shown below. You conduct the reaction and find that you actually get 0.90 g of H2. What is
your percent yield?
2NH3 
decomposition
Stoichiometry Unit Worksheet #9: Percent Yield
percentage yield = actual amount of product X 100 (Calculation is just like calculating your % on a quiz)
expected amount of product
Example 1: A student conducts a reaction that produces 2.755 grams of copper. Mathematically he
determines that 3.150 grams of copper should have been produced. Calculate the student's % yield.
Answer: actual amount of product
X 100 = 2.755 g X100 = 87.5%
expected amount of product
3.150 g
1.
In the reaction shown below, a student produces 22 grams of water. Mathematically he determines that 29
grams of water should have been produced. Calculate the student's percentage yield.
2H2 + O2 
synthesis
2.
The actual amount of MgO synthesized in the reaction shown below was 0.77 g. If the theoretical amount of
MgO was calculated to be 1.30 g, what is the percent yield of the reaction?
2Mg + O2 
synthesis
3.
A chemist starts with 11.2 g of KClO3 and calculates that it should be possible to make 7.6 g of KCl with that
much KClO3. After having conducted the reaction, she finds that she recovered only 6.8 g of KCl. What is her percent
yield?
2KClO3 
Decomposition (oxygen is one of the 2 products)
4.
You have 6.2 g of NH3 in the cabinet. You do a short calculation and figure out that this much NH3 will yield
0.92 g of H2 in the reaction shown below. You conduct the reaction and find that you actually get 0.90 g of H2. What is
your percent yield?
2NH3 
decomposition