1. Finding the Theoretical and Experimental Yield
By. Jylyan Velasco

2. Definitions Yield: the amount of desired product
Theoretical Yield: maximum possible yield that can be obtained
Actual (Experimental) Yield: the amount actually produced of a product (usually given)
Percent Yield: Percent ratio of the actual yield to the theoretical yield

3. Formula

4. How to Find the Theoretical Yield: Method 1
Find the molar mass of what is being heated
Find the mol using the molar mass (divide the mass that is being given by the molar mass)
Multiply the mol of what is being heated by the molar mass of what is being obtained

5. How to Find the Theoretical Yield: Method 2
**USE DIMENSIONAL ANALYSIS!!!

6. How to find the Percentage Yield
Divide the actual yield by the theoretical yield
Multiply by 100%

7. When 5.00 g. of P reacts with excess Cl2, 17.2 g. of PCl3 is obtained. 2P + 3Cl2 → 2PCl3: Method 1
Molar mass of P = 30.9 g/mol^-1
5.00g P / 30.9 g/mol^-1 P = .162 mol P
Molar mass of PCl3 = 137 g/mol^-1
.162 mol P x 137 g/mol ^-1 = 22.2 g.
17.2 g. / 22.2 g. = .774
.774 x 100 = 77.4%
The percentage yield of PCl3 is 77.4%

8. Method 2

9. When 2. 50g of SO2 is heated with excess oxygen, 2
When 2.50g of SO2 is heated with excess oxygen, 2.50g of SO3 is obtained. 2SO2+O2→2SO3: Method 1
Molar mass of SO2 = 64.1 g/mol^-1
2.50g SO2 / 64.1 g/mol^-1 SO2 = mol SO2
Molar mass of SO3 = 80.1 g/mol^-1
0.039 mol SO2 x 80.1 g/mol^-1 SO3= 3.12g
2.50g / 3.12g = *THE ACTUAL YIELD IS ALREADY GIVEN!!!
.801 x 100 = 80.1%
The percentage yield of SO3 is 80.1%

10. Method 2

11. When 10. 0g of arsenic is heated in excess oxygen, 12
When 10.0g of arsenic is heated in excess oxygen, 12.5g of 4AsO6 is produced. 4As + 3O2 → As4O6
Molar mass of 4As = 300 g/mol^-1
10.0g As / 300 g/mol^-1As = .033 mol As
Molar mass of As4O6 = 396 g/mol^-1
.033 mol As x 396 g/mol^-1 = 13.1 g
12.5g / 13.1g = *THE ACTUAL YIELD IS ALREADY GIVEN
.954 x 100 = 95.4%
The percentage yield of As4O6 is 95.4%

12. When 1. 20g of C2H4 reacts with excess bromine, 5
When 1.20g of C2H4 reacts with excess bromine, 5.23g of CH2BrCH2Br is produced. C2H4 + Br2 → CH2BrCH2Br

13. Sulfur trioxide, SO3 can be produced in the following two-step reaction: 4FeS → 2Fe2O3 + 8SO2
2SO2 + O2 →2SO3
30.0 g of iron disulfide, FeS2 reacts in the presence of excess oxygen to completion.
Calculate the theoretical yield, in g, of sulfur trioxide.
If an experimental yield of 28.0 g of sulfur trioxide is achieved, deduce the percentage yield.

14. Part A

15. Part B
28.0 g / 40.1 g = .698
.698 x 100 = 69.8
Theoretical Yield = 69.8%

16. Important Notes to Remember
The Actual Yield is usually given
Ignore the word excess and the element that goes along with it
ALWAYS PUT IN UNITS