1. Thanks to Piedra Vista High, School, Farmington, NM
Percent Yield
Thanks to Piedra Vista High, School, Farmington, NM

2. Objective: learn to calculate actual yield as a percentage of theoretical yield.
Using stoichiometry we found the amount of product that could be formed.
This is the Theoretical Yield.

3. Real Life
The theoretical yield is very rarely obtained.
Why????

4. Actual yield This is the amount of product actually obtained.
The comparison of Theoretical and Actual is called the PERCENT YIELD
Actual yield X 100 = percent yield
Theoretical yield

5. Problem:
Methanol can be produced by the reaction between carbon monoxide and hydrogen. Suppose 68.5 Kg(6.85X104g) of CO(g) is reacted with 8.60 Kg (8.60X103g) of H2
A) Calculate the theoretical yield of Methanol (CH3OH)

6. Step 1:
Balanced equation
2H2(g) + CO(g)  CH3OH(l)
Step 2:
Find the limiting reactant
Solve for the amount of methanol that can be produced with each reactant.
H2 is limiting

7. You now have the theoretical yield for methanol.
Calculate the number of grams of Methanol theoretically produced.
6.86X104 grams of CH3OH

8. Percent Yield
If 3.57 X 104 g of CH3OH is actually produced what is the percent yield of methanol?
Actual yield (grams) X100
Theoretical yield (grams)
3.57X104 gCH3OH X100 = 52.0%
6.86X104 g CH3OH

9. New problem
Solid titanium(IV) oxide can be prepared by reacting gaseous titanium (IV) chloride with oxygen gas. A second product of this reaction is chlorine gas.
TiCl4(g) + O2(g) TiO2(s) + Cl2(g)
A. Suppose 6.71 X103 g of titanium (IV) chloride is reacted with 2.45 X103g of oxygen. Calculate the maximum mass of titanium (IV) oxide that can form.

10. 2.83 X103g TiO3
If the percent yield of TiO2 is 75% what mass is actually formed??
Actual yield (grams) X100
Theoretical yield (grams)
2.12 X 103g of TiO2 is actually obtained

11. Practice!!!!