Percentage Yield
To find the percentage yield, there are a few simple steps!
If you have completed the previous two lessons on finding limiting reagents and theoretical yield then you are fully equipped to work on this. If you haven't, however, click on their links to go back and review the lessons on them.

Here are the formulas that you will need for this lesson:
Percentage Yield=  Actual Yield/Theoretical Yield * (100) 
Theoretical Yield = (Molar Mass of Product/Molar Mass of Reactant)*(Mass of Reactant)

Let's use this practice problem to guide us:
For the balanced equation shown below, if the reaction of 91.0 grams of O2 produces 215 grams of Cl2, what is the percent yield?
                                                                                              CCl4+O2=>CO2+2Cl2

STEP 1:
Determine the knowns and unknowns that we are given in the problem by plugging the values into the formula.
This problem gives us actual yield (which can be determined by looking for the phrase  : "produces .... grams". The ... would be the amount of grams) which is  215 grams. 
We are also able to find the theoretical yield using the rest of the information that was given to us (91.0 grams of O2).

STEP 2: 
Calculate the theoretical yield. 
The question already tells you the limiting reagent since it says that the reaction happens between O2 and the product Cl2. 
So let's get to it!

O2= 32g/mole
Moles of O2= 2.84
Second Ratio=1:2
Molar Mass of Cl2=71g/mole
Final Equation=
            2.84(2)=5.68
           5.68(71)=403.28grams

STEP 3:
Solve for percentage yield.

Now that we know the actual yield and we have calculated the theoretical yield, we can plug all of the information into our equation to solve for the percentage yield as the question asks.
Follow the steps below:

And there it is, you have found your percentage yield!
Click here to continue on to some practice problems!!!