Stoichiometry Loose Ends - Limiting Reactants, Percentage Yield and Percentage Error
What is a ____________________ ______________________?
The ____________________ that controls the quantity of ___________________ that can form in a chemical
reaction.
In other words, the ______________________ that ______________________ the reaction because you run out of it.
Every other reactant is called the __________________________ reactants.
How can we determine what is going to be the limiting reactant?
Convert _______ reactants into the same product with the _________________ substance unit.
The one that produces ______________ product is the _____________________ reactant.
Percentage Yield - The ________________________ of the experimental yield to the theoretical yield
_________________________ yield – book value, “correct answer,” the calculated value, value you were aiming at.
__________________________________ yield – measured value, experimental value, value you got in the lab
Formula - Divide the __________________________ value by the ________________________ yield and multiply
by 100.
Percentage Error - The margin of _________________________ expressed as a _____________________________.
Formula
Take the theoretical yield and ___________________________ the experimental value.
Divide this value by the _______________________________ yield and multiply by 100%
Example with Stoichiometry:
PCl3 + 3 H2O  H3PO3 + 3 HCl
Theoretically, how many grams of phosphorous acid, H3PO3, can be obtained if 225 g of PCl3 was used?
Theoretically, how many grams of phosphorous acid, H3PO3, can be obtained if 123 g of H2O was used?
What is the limiting reactant?
If 100 g of H3PO3 was recovered in the experiment, what is the percent yield and percent error?
Name:
Block:
Limiting Reactant, Percent Yield, and Percent Error Homework
1) If the theoretical yield of an experiment is 69.2 g and the experimental yield was 52.3 g, what was the percentage
yield and percentage error?
2)
Reacting 1.52 mol of SiO2 with excess carbon yields 43.7 g of CO according to the reaction:
SiO2 + 3C  SiC + 2CO.
a. What is the theoretical yield of SiC (how many grams of SiC can be made)?
b.
What is the percentage yield?
c.
What is the percentage error?
3) If 156 g of sodium nitrate decomposes according to the reaction 2NaNO3  2NaNO2 + O2, and 112 g of sodium
nitrite are recovered from the experiment,
a. What is the theoretical yield of sodium nitrite?
b.
What is the percentage yield?
c.
What is the percentage error?
4) Using this equation, answer the following questions:
a.
___ Fe + ___ H2O  ___ Fe3O4 + ___ H2
Theoretically, how many grams of Fe3O4 can be obtained if 16.8 g of Fe was used?
b.
Theoretically, how many grams of Fe3O4 can be obtained if 10 g of H2O was used?
c.
Using part a and b, what is the limiting reactant and what is the excess reactant?
d. If 20.1 g of Fe3O4 was recovered in the experiment, what is the percent yield and percent error?