1. Lecture 4.5 – Percent Yield

2. Today’s Learning Targets
LT 4.9 – I can hypothesize and calculate the percent yield for a given chemical reaction.

3. What is percent yield?

4. I. Percent Yield
Stoichiometry tells us what should happen for a reaction. This is the theoretical yield.
We predict using stoichiometry conversions
The amount that a reaction actual produces is known as the actual yield.

5. How do we calculate percent yield?

6. I. Calculating the Percent Yield
Percent yield can be calculated by the equation:
Calculate the theoretical yield using stoichiometry.
Often, you experiment to obtain the actual yield.

7. Class Example I perform the following reaction: 2H2 + O2  2H2O
and I predict that I will produce 18 g of H2O. If I actually produce 16 g of H2O, then what is my percent yield?

8. 4 KI + K4(CrO4) 2  2 I2 + 2 K2O + K4(CrO3) 2
Class Example
I perform the following reaction:
4 KI + K4(CrO4) 2  2 I K2O + K4(CrO3) 2
I react 332 g of KI with excess K4(CrO4)2. If I actually produce g of I2, what is my percent yield for the reaction?