Name ____________
Period ________________
Percent Yield
% yield = (actual yield of product / theoretical yield of product) x 100
actual yield = measured amount of product obtained from a reaction
theoretical yield = maximum amount of product that could possibly be produced from a given
amount of reactant (if the reaction went to completion)
Example:
C6H6 + Cl2 →C6H5Cl + HCl
When 36.8 grams of C6H6 react with an excess of Cl2, the actual yield of C6H5Cl is 38.8g. What
is the percent yield of C6H5Cl?
1) The actual amount of product in a reaction is 39.7g although a mass-mass calculation
predicted 65.6g. What is the percentage yield of this product?
2) What is the percent yield in the following reaction if 5.50 grams of hydrogen react with
nitrogen to form 20.4 grams of ammonia? N2 + 3H2 →2NH3
3) Chromium (III) hydroxide solution will dissolve in concentrated sodium hydroxide solution
according to the following equation: NaOH + Cr(OH)3 →NaCr(OH)4
This process is one step in making high purity chromium chemicals. If you begin with 66.0g
Cr(OH)3 and obtain 38.4g of NaCr(OH)4, what is your percent yield?
4) A calculation indicates that 82.8g of a product should be obtained from a certain reaction. If a
chemist actually gets 30.7g, what is the percent yield?
5) From the information given, calculate the % yield for each.
a. theoretical yield = 20.0g actual yield = 15.0g
b. theoretical yield = 24.0g actual yield = 22.5g
c. actual yield = 4.75g
theoretical yield = 5.00g
Practice Problems (cont’d)
6. If 21.4g of aluminum is reacted with excess Fe2O3, the products will be Al2O3 and iron. What
mass of iron will be produced?
7. If 41.6g of N2O4 reacts with excess N2H4, the products will be nitrogen and water. What
mass of water will be produced?
8. If 16.8g of CO is mixed under high pressure with excess H2, what mass of methanol (CH3OH)
will be produced?
9. What mass of NaCl will be produced by the reaction of 58.7g of NaI with excess Cl2 gas if
the products are sodium chloride and I2?
10. Determine the percent yield for the reaction between 3.74g of Na and excess O2 if 5.34g of
Na2O2 is recovered.
11. Determine the percent yield for the reaction between 6.92g of K and excess O2 if 7.36g of
K2O is produced.
12. Determine the percent yield for the reaction between 82.4g of Rb and excess O2 if 39.7g of
Rb2O is produced.