Transcript sample problem

Chemistry 16.3
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12.3
Limiting Reagent and Percent Yield
If a carpenter had two tabletops and
seven table legs, he could only build
one four-legged table. The number
of table legs is the limiting factor in
the construction of four-legged
tables. Similarly, in chemistry, the
amount of product made in a
chemical reaction may be limited by
the amount of one or more of the
reactants.
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12.3
Limiting Reagent and Percent Yield
> Limiting and Excess
Reagents
Limiting and Excess Reagents
How is the amount of product in a
reaction affected by an insufficient
quantity of any of the reactants?
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12.3
Limiting Reagent and Percent Yield
> Limiting and Excess
Reagents
In a chemical reaction, an insufficient
quantity of any of the reactants will limit
the amount of product that forms.
The limiting reagent is the reagent that
determines the amount of product that can
be formed by a reaction.
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12.3
Limiting Reagent and Percent Yield
> Limiting and Excess
Reagents
In the reaction of nitrogen and hydrogen,
hydrogen is the limiting reagent. Nitrogen is the
reagent that is not completely used up in the
reaction. The reagent that is not used up is
called the excess reagent.
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12.3
Limiting Reagent and Percent Yield
> Limiting and Excess
Reagents
The Chemical Equation for the
Preparation of Ammonia
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Limiting Reagent and Percent Yield
> Limiting and Excess
Reagents
Animation 13
Apply the limiting reagent concept to the
production of iron from iron ore.
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SAMPLE PROBLEM 12.7
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SAMPLE PROBLEM 12.7
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SAMPLE PROBLEM 12.7
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SAMPLE PROBLEM 12.7
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Practice Problems for Sample Problem 12.7
Problem Solving 12.25
Solve Problem 25 with the
help of an interactive
guided tutorial.
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SAMPLE PROBLEM 12.8
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SAMPLE PROBLEM 12.8
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SAMPLE PROBLEM 12.8
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SAMPLE PROBLEM 12.8
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Practice Problems for Sample Problem 12.8
Problem Solving 12.28 Solve
Problem 28 with the help of an
interactive guided tutorial.
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12.3
Limiting Reagent and Percent Yield
> Percent Yield
Percent Yield
What does the percent yield of a
reaction measure?
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12.3
Limiting Reagent and Percent Yield
> Percent Yield
The percent yield is a measure of the
efficiency of a reaction carried out in the
laboratory.
A batting average is actually a percent yield.
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12.3
Limiting Reagent and Percent Yield
> Percent Yield
• The theoretical yield is the maximum amount
of product that could be formed from given
amounts of reactants.
• In contrast, the amount of product that
actually forms when the reaction is carried out
in the laboratory is called the actual yield.
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12.3
Limiting Reagent and Percent Yield
> Percent Yield
The percent yield is the ratio of the actual
yield to the theoretical yield expressed as
a percent.
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SAMPLE PROBLEM 12.9
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SAMPLE PROBLEM 12.9
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SAMPLE PROBLEM 12.9
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SAMPLE PROBLEM 12.9
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Practice Problems for Sample Problem 12.9
Problem Solving 12.29
Solve Problem 29 with the
help of an interactive
guided tutorial.
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SAMPLE PROBLEM 12.10
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SAMPLE PROBLEM 12.10
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SAMPLE PROBLEM 12.10
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SAMPLE PROBLEM 12.10
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Practice Problems for Sample Problem 12.10
Problem Solving 12.31
Solve Problem 31 with the
help of an interactive guided
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tutorial.
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12.3 Section Quiz.
Assess students’ understanding
of the concepts in Section 12.3.
Continue to:
-or-
Launch:
Section Quiz
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12.3 Section Quiz.
1. In the reaction 3NO2 + H2O  2HNO3 + NO,
how many grams of HNO3 can form when
1.00 g of NO2 and 2.25 g of H2O are allowed
to react?
a. 0.913 g
b. 0.667 g
c. 15.7 g
d. 1.37 g
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12.3 Section Quiz.
2. How many grams of H2O can be formed from
24.0 g O2 and 6.00 g H2?
a. 30.0 g
b. 27.0 g
c. 54.0 g
d. 13.5 g
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12.3 Section Quiz.
3. Octane burns according to the following equation.
2C8H18 + 25O2  16CO2 + 18H2O
What is the percent yield if 14.6 g of CO2 are produced
when 5.00 g of C8H18 are burned?
a. 106%
b. 94.8%
c. 34.2%
d. 62.5%
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Limiting Reagent and Percent Yield
> Concept Map 12
Solve the Concept Map with the help of an
interactive guided tutorial.
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END OF SHOW