Stoichiometry
Objectives:
• Identify what stoichiometry is in chemistry.
• Apply stoichiometry calculations in chemical
reactions.
• Identify and apply limiting reagents in
chemical reactions.
• Calculate % yield of products in a chemical
reaction.
Chemistry: 5.5
Due:
Percent Composition Worksheet (late)
Objectives:
Complete Chemical Quantities Exam
Define stoichiometry
Homework:
Define stoichiometry.
Chemistry: 5.6
Infinite Campus Update:
• Percent Composition Worksheet(10pts.)
• Bubble Gum Lab (10pts.)
Objectives:
• Identify and apply stoichiometry with substances
in a chemical equation. (mole to mole)
Homework:
Stoichiometry problems: mole to mole conversions
What is Stoichiometry?
access.aasd.k12.wi.us
Stoichiometry
N2 +
3H2 ---------->
What is stoichiometry?:
(NH3)
www.larapedia.com
2NH3
(N2)
N2
Stoichiometry
+
3H2
---------->
(NH3)
www.larapedia.com
2NH3
(N2)
Chemistry: 5.8.14
Due:
• Stoichiometry Problems (moles to mass)
Objectives:
• Identify and apply stoichiometry with substances
in a chemical equation. (mole to mole and mass
to mass)
• Stoichiometry Gallery Walk
Homework:
Quiz tomorrow over stoichiometry conversions.
Stoichiometry Lab
Stoichiometry Gallery Walk
Chemistry: 5.9.14
Due:
• Stoichiometry Problems (mass to mass)
Objectives:
• Identify and apply stoichiometry with substances
in a chemical equation. (mole to mole and mass
to mass)
• Stoichiometry Quiz
Homework:
Stoichiometry Problems
Stoichiometry
www.larapedia.com
Stoichiometry
N2 +
3H2 ---------->
2NH3
Stoichiometry:
• Converting between substances in a balanced
chemical equation using mole conversions.
(NH3)
www.larapedia.com
(N2)
Chemistry: 5.7
Posted in Infinite Campus and LATE if not turned in!
• Percent Composition Worksheet(10pts.)
• Bubble Gum Lab (10pts.)
Objectives:
• Identify and apply stoichiometry with substances
in a chemical equation. (mole to mole and mass
to mass)
Homework:
Stoichiometry problems: mass to mass
Stoichiometry: Bell Ringer
H2O ----------> H2 +
O2
1. What type of reaction is this?
2. Balance the chemical equation if needed.
3. If you start with 100 moles of H2O how many moles of
H2 would be produced?
3. If you want to produce 3.8moles of O2, how many grams
of H2O would you need to start with?
Stoichiometry
www.larapedia.com
Stoichiometry
www.larapedia.com
Stoichiometry
www.larapedia.com
Stoichiometry Problems
N2H4 +
•
O2 ----->
N2 + 2 H2O
If 13.8 grams of water were produced how much
rocket fuel (N2H4) in grams would have been used
up?
Chemistry (4/29)
Objectives:
• Complete post-lab questions for Hydrate Lab.
• Identify and apply stoichiometry with substances in
a chemical equation.
Homework:
Stoichiometry Problems
Cu(SO4)
.
Hydrate Lab
H2O ----> Cu(SO4) + H2O
Post-Lab questions:
Use the equation above to help answer the following
questions:
1. What was the hydrate salt in this experiment?
2. What was the anhydrous salt in this experiment?
3. What was the difference between the hydrated salt
and the anhydrous salt in this experiment?
4. Was this a physical or chemical reaction? Validate your
answer with data from your lab.
Cu(SO4)
.
Hydrate Lab
H2O ----> Cu(SO4) + H2O
Copper Sulfate Hydrate
Chemistry (5/1)
Infinite Campus Update:
• Chemical Quantities Exam (37pts)
• Hydrate Lab (10pts.)
Objectives:
• Identify and apply stoichiometry with substances in
a balanced chemical equation.
Homework:
Stoichiometry Problems
Bell Ringer
1. Calculate the percent composition of water in this
hydrate: Mg(SO4)
. 7H O
2
(Epsom Salt)
2. What is stoichiometry?
3.
N2H4 +
O2 ----->
N2 + H2O
a. Balance the chemical equation.
b. How many moles of rocket fuel (N2H4) are needed to
produce 8 moles of N2?
Bell Ringer
1. Calculate the percent composition of water in this
hydrate: Mg(SO4)
. 7H O
2
(Epsom Salt)
2.What is stoichiometry?
3.
N2H4 + O2 -----> N2 + H2O
a. Balance the chemical equation.
b. How many moles of rocket fuel (N2H4) are needed to
produce 8 moles of N2?
Bell Ringer
1. Calculate the percent composition of water in this
hydrate: Mg(SO4)
. 7H O
2
(Epsom Salt)
2. What is stoichiometry?
3.
N2H4 +
O2 ----->
N2 + H2O
a. Balance the chemical equation.
b. How many moles of rocket fuel (N2H4) are needed to
produce 8 moles of N2?
Stoichiometry
N2 +
3H2 ---------->
2NH3
Stoichiometry:
• Converting between substances in a balanced
chemical equation using mole conversions.
(NH3)
www.larapedia.com
(N2)
Stoichiometry
H2O ----------> H2 +
O2
1. What type of reaction is this?
2. Balance the chemical equation if needed.
3. If you start with 100 moles of H2O how many moles of
H2 would be produced?
3. If you want to produce 3.8moles of O2, how much H2O
will you need to start with?
Chemistry (5/2)
Objectives:
• Identify and apply stoichiometry with substances in
a balanced chemical equation.
Homework:
Stoichiometry Problems
Chemistry (5/6)
Objectives:
• Identify and apply stoichiometry with substances in a
balanced chemical equation.
Homework:
Stoichiometry Problems (due Wed.)
Gas Laws Graphing Assignment (due Wed.)
Quiz: Wednesday (Stoichiometry conversions: mole to mole
or grams to grams.)
Stoichiometry
N2 +
3H2 ---------->
2NH3
Stoichiometry:
• Converting between substances in a balanced
chemical equation using mole conversions.
www.larapedia.com
Stoichiometery Problems
Stoichiometry Lab
Na(HCO3) + H(C2H3O2) --> CO2 + H2O + Na(C2H3O2)
Objectives:
• Complete lab and answer post lab questions.
• Pass-out/ review study guide questions
Homework:
• Review for exam-test Wed.
Stoichiometry Lab Data
Group #
1
2
3
4
5
6
7
8
Theoretical
Actual Yield
Yield Na(C2H3O2) Na(C2H3O2)
% Yield of
Na(C2H3O2)
Stoichiometry: Limiting Reactants
• Limiting Reactant:
• Excess Reactant:
en.wikipedia.org
Stoichiometry: Limiting Reactants
• Limiting Reactant: completely consumed
• Excess Reactant: partially consumed
en.wikipedia.org
Stoichiometry: Limiting Reactant
HCl + Mg -------> MgCl2 + H2
1. What type of reactions is this?
2. Balance equation if needed.
3. If 6.8 moles of Mg react with 7.5 moles of HCl which is
considered the limiting reactant? excess reactant?
Reactants
Have (moles) Need (moles)
Stoichiometry: Limiting Reactant
2HCl + Mg -------> MgCl2 + H2
1.If 6.8 moles of Mg react with 7.5 moles of HCl how
many moles of MgCl2 can be produced?
Reactants
Have (moles) Need (moles)
HCl (limited)
7.5 mol
13.6
Mg (excess)
6.8 mol
3.75
Theoretical vs. Actual Yield of Products
• Theoretical yield: maximum amount that can be
produced according to the limiting reactant.
(calculated yield)
• Actual yield: actual amount produced in the lab.
Stoichiometry: Limiting Reactant
4. Limiting Reactant: Al
Theoretical Yield of AlCl3: 3.0 moles
5. Limiting Reactant: C2H4
Theoretical yield of H2O: 5.4 moles
6. Limiting Reactant: N2
Theoretical yield of NH3: 34 g
Limiting Reactant
Stoichiometry: Percent Yield
4. Theoretical Yield of AlCl3: 3.0 moles
Actual yield from lab of AlCl3: 2.8 mole
% Yield of AlCl3 :
5. Theoretical yield of H2O: 5.4 moles
Actual yield from lab of H2O: 4.9 moles
% Yield of H2O:
6. Theoretical yield of NH3: 34 g
Actual yield from lab of NH3: 31.5 g
% yield of NH3:
Stoichiometry: Percent Yield
% Yield of Product:
Accuracy of product formation in the lab.
% Yield of product: actual yield
x 100
theoretical yield
Actual yield: actual amount formed in lab
Theoretical yield: maximum amount that can be
produced according to the limiting reactant.
(calculated yield)
Pre-AP Chemistry 4/26
Objectives:
• Identify and apply limiting reactants in
stoichiometric calculations.
• Distinguish between theoretical and actual
yield.
• Calculate % yield.
Homework:
Limiting and % Yield worksheets.
Pre-AP Chemistry (4/29)
Objectives:
• Identify and apply limiting reactants in a chemical
equation.
• Calculate percent yield of products in a chemical
equation.
• Identify what molarity is.
Homework:
• Complete Limiting and % Yield worksheet.
• Read over lab and complete hypothesis section.
*Quiz: Wednesday over stoichiometry, limiting
reactants, and percent yield of products.
Bell Ringer: Limiting Reactants and % Yield
1.
2.
a.
b.
c.
C2H2 + O2 --- CO2 + H2O
Balance the equation if needed.
If 2.40 moles of C2H2 reacts with 7.40 moles of
O2 how many grams of water can be produced?
What is the limiting reactant?
Use limiting reactant to calculate theoretical
yield of H2O in grams.
If the actual yield of H2O in the lab was 40.1
grams, calculate what the % yield of H2O would
be.