P ERCENT Y IELD. OBJECTIVE I can calculate percent yield of a reaction.
14
PERCENT YIELD
Transcript of P ERCENT Y IELD. OBJECTIVE I can calculate percent yield of a reaction.
PERCENT YIELD
OBJECTIVE
I can calculate percent yield of a reaction
THEORETICAL YIELD
Theoretical yield is the maximum amount of product that could be formed from given amounts of reactants.
Theoretical yield is calculated using the gram to gram stoichiometry roadmap.
ACTUAL YIELD
Actual yield is actual measured amount of product formed when the reaction is carried out in the lab.
Actual yield is an experimental value. You do an experiment and measure the mass of the product formed.
PERCENT YIELD
Percent yield is the ratio of the actual yield to the theoretical yield expressed as a percent.
Example 1:
2 H2 + O2 2H2O
Using stoichiometry, you calculate that a reaction of oxygen gas in an excess of hydrogen gas would yield 28.3 g of water.
28.3 g H2O = theoretical yield
Perform the experiment in the lab and you measure 26.3 g of water produced.
26.3g H2O = actual yield
% ? %1003.28
3.26 Yield %
g
g
Example 1:
2 H2 + O2 2H2O
You calculate that a reaction of oxygen gas in an excess of hydrogen gas would yield 28.3 g of water.
28.3 g H2O = theoretical yield
Perform the experiment in the lab and you measure 26.3 g of water produced.
26.3g H2O = actual yield
92.9% %1003.28
3.26 Yield %
g
g
EXAMPLE 2
Balance the equation. ____NO2 + ____H2O ____HNO3 + ____NO
EXAMPLE 2
3 NO2 + H2O 2 HNO3 + NO
a. 9.55 g of NO2 will be used in this reaction. Calculate the amount (grams) of HNO3 that is possible to produce with this amount of NO2. (the theoretical yield)
9.55 g NO2 x _____________ x _____________ x ____________ = ______ g HNO3
EXAMPLE 2
3 NO2 + H2O 2 HNO3 + NO
a. 9.55 g of NO2 will be used in this reaction. Calculate the amount (grams) of HNO3 that is possible to produce with this amount of NO2. (the theoretical yield)
9.55 g NO2
x= 8.72 g HNO346.0 g
NO2
3 mol NO2
1 mol NO2 x 2 mol HNO3 x
1 mol HNO3
63.0 g HNO3
Theoretical Yield
EXAMPLE 2 – THE PERCENT YIELD
In the lab, an excess of water is mixed with the NO2, and the reaction is allowed to run until completion.
The products are weighed and there is 7.23 g of HNO3 left over (the actual yield).
Calculate the percent yield of the experiment.
EXAMPLE 2 In the lab, an excess of water is mixed with
the NO2, and the reaction is allowed to run until completion.
The products are weighed and there is 7.23 g of HNO3 left over (the actual yield).
Calculate the percent yield of the experiment.
% ? 10072.8
23.7%
g
gYield
EXAMPLE 2 In the lab, an excess of water is mixed with
the NO2, and the reaction is allowed to run until completion.
The products are weighed and there is 7.23 g of HNO3 left over (the actual yield).
Calculate the percent yield of the experiment.
%9.8210072.8
23.7%
g
gYield
OBJECTIVE
I can calculate percent yield of a reaction
