Calculating Theoretical Yield, Actual Yield and Percent Yield
Theoretical Yield – in theory, in optimum situations, this is the maximum amount one could
form if all reactant is used up.
Actual Yield – in a lab, during a reaction this is the actual amount that was formed. It is not
the same at T.Y. because chances are not every atom will react or some could get “lost”. In
most cases, this information is given to you.
Percent Yield – when one compares what was actually formed to how much one thought they
would form. The equation is as follows:
(Actual yield  Theoretical yield)  100 = Percent yield
1.
In the commercial production of arsenic, arsenic (III) oxide is heated with carbon, which reduces
the oxide to the metal according to the following equation:
2 As2O3 + 3 C  3 CO2 + 4 As
a.
2.
If 8.87 grams of arsenic (III) oxide is used in the reaction and 5.33 grams of As is produced,
what is the percent yield?
Nitrogen dioxide can be reacted with ozone, O3, and will form dinitrogen pentoxide. Oxygen is
also formed. If a reaction occurs in which 0.38 gram of nitrogen dioxide is used and only 0.36
grams of dinitrogen pentoxide is recovered, what is the percent yield of this reaction?
Write the balanced equation:
Calculate the amount of product we should form (Theoretical Yield), if all reactant is used:
Calculate Percent Yield:
3.
Use the above equation – What mass of N2O5 will form from a reaction of 6.0 mol of NO2 if there
is a 61.1% yield?
4.
If 12.5 g of copper are reacted with an excess of chlorine gas, then 25.4 g of copper (II) chloride
are obtained. Calculate the theoretical yield and the percent yield.
5.
In the reaction of zinc with hydrochloric acid, 140.15 g of zinc chloride was formed. If the
theoretical yield was 143 g, how much zinc must have been involved in the reaction? What was
the percent yield?
6.
If 6.57 g of iron are reacted with an excess of hydrochloric acid, the hydrogen gas and 14.63 g of
iron (II) chloride are obtained. Calculate the theoretical yield and the percent yield.