Stoichiometry wk 2 Lesson Plan
Name: Sara Adamek
Class/Subject: AP Prep Chemistry
Date: March/April 31- 4, 2014
Student Objectives/Student Outcomes:
Objectives
Assessment
Students will be able to
Students will correctly identify given information, choose the correct
covert between amounts conversion factor(s) and then solve the problem correctly.
of one substance and
amounts of another.
Students will be able to
Stoichiometry allows you to determine yields and limiting reagents, both of
explain why this skill is
which have applications in industry and research. Presumably it also boosts
useful.
logical thinking and problem solving.
Students will be able to
Students will be able to solve stoichiometric problems and then choose the
identify the limiting
reactant that will limit the production of the product.
reagent.
Content Standards:
HS-PS1 Matter and its Interactions
HS-PS1-7.
Use mathematical representations to support the claim that atoms, and therefore
mass, are conserved during a chemical reaction.
Materials/Resources/Technology:
Stoichiometry challenge problems, stoichiometry mixed practice
Time (Review stoich)
Start of Class:
What is stoichiometry? (Calculations relating to finding out how much stuff is needed/will
be produced)
Why is it useful? (Can’t go around just dumping chemicals together.)
Announce quiz on Thursday.
Introduction of Lesson:
Demo grams to moles and then grams to grams.
Lesson Instruction:
Pass out Practice problems. Do first problem with students. Release students to work.
Assessment/Checks for understanding:
Check for completion. Give feedback
Closure/Wrap-up/Review:
Round students up for exit slip explanation.
Ask them to answer the questions: If you are given a starting mass and a balanced equation
how would you solve for the mass of product. There are 4 steps (five if you count solving the
problem.
Materials/Resources/Technology:
Baking soda, HCl, Mole and Mass Relationships lab guide
Time (Lab)
Start of Class:
Collect hw. Take attendance.
Introduction of Lesson:
Pass out Lab. Discuss procedure and safety.
Lesson Instruction:
Have students do the lab.
Assessment/Checks for understanding:
Grade lab questions for accuracy. Provide feedback.
Closure/Wrap-up/Review:
If there is time, gather students and discuss lab outcomes/ calculations.
Materials/Resources/Technology:
Time (Lab wrap up/ Mole : gram review)
Start of Class:
Take attendance. Pass back papers.
Introduction of Lesson:
Review key points of the lab.
Lesson Instruction:
Review Mass to mass calculations. Have students work on lab or review questions.
Assessment/Checks for understanding:
Grade lab for accuracy. Check HW for completion. Provide feedback for both.
Closure/Wrap-up/Review:
Exit slip. Given Al + Br2  AlBr3 and 5.4 grams of Br2 how many grams of AlBr3 are you
going to end with?
Materials/Resources/Technology:
Time ( Quiz)
Start of Class:
Collect HW and lab. Pass back papers. Take attendance
Introduction of Lesson:
Pass out conversion quiz.
Have students pick up A mole is not a Furry Rodent rubric and read when finished.
Lesson Instruction:
Discuss ‘A Mole is Not…Assignment’ with students. Emphasize that no class time will be
given to work on it. Allow time for students to go look at past years’ projects.
Answer questions about the Mole project.
Introduce Scientific notation.
Assessment/Checks for understanding:
Check activity for completion.
Closure/Wrap-up/Review:
Materials/Resources/Technology:
Extra copies of ‘A Mole is not a Furry Rodent’
Time (Field Trip with Substitute)
2 min
Start of Class:
Take attendance.
Introduction of Lesson:
Pass out the worksheet STOICHIOMETRY: Field trip pts. Instruct the students that they are
to show all their work or they need to fill in the blanks provided. This will be due at the end
of the hour; please collect it. Students my use their notes and other materials to work on the
problems.
They may not use their phones. (Unless they are using them as calculators, but the difference
is pretty easy to spot.)
They may talk quietly but if the conversations get off topic/ too loud feel free to require them
to work silently. You can let them know up front that if they are not on topic they will have
to work silently.
If students finish the worksheet early they many work on their project “A Mole is not a Furry
Mammal” or they may work on other homework.
They will try to pack up early and line up at the door. Try to keep them in their seats and
working.
Lesson Instruction:
Students should work on the worksheet and then ‘A Mole is not a Furry Rodent’ projects.
Assessment/Checks for understanding:
Check wks for completion. Give feedback.
Closure/Wrap-up/Review:
Collect the stoichiometry worksheet.
STOICHIOMETRY: CHALLENGE PRACTICE
Name:____________________
1. Given ____ (NH4)2Cr2O7  ___ Cr2O3 + ____ N2+ ____ H2O
a. What mass of Cr2O3 will be produced given 10.8 g (NH4)2Cr2O7?
b. What mass of N2 will be produced given 10.8 g (NH4)2Cr2O7?
c. What mass of H2O will be produced given 10.8 g (NH4)2Cr2O7?
2. Over the years, the thermite reaction has been used for welding railroad rails, in incendiary
bombs, and to ignite solid-fuel rocket motors. The reaction is:
Fe2O3 (s) + 2 Al (s)  2 Fe (l) + Al2O3 (s)
a. What mass of iron (III) oxide and aluminum must be used to produce 15.0 g iron?
b. What is the maximum mass of aluminum oxide that could be produced?
3. The reusable booster rockets of the U.S. space shuttle employ a mixture of aluminum and
ammonium perchlorate for fuel. A possible equation for this reaction is
3 Al + NH4ClO4  Al2O3 + AlCl3 + 3NO + 6 H2O
a. What mass of NH4ClO4 should be used in the fuel mixture for every kilogram of Al?
4. One of the relatively few reactions that takes place directly between two solids at room
temperature is below. In this equation, the ˖ 8 H2O indicates the presence of eight water
molecules. Therefore the compound is called barium hydroxide octahydrate.
Ba(OH)2 ˖ 8 H2O + NH4SCN  Ba(SCN)2 + H2O + NH3
a. Balance the equation.
b. What mass of ammonium thiocynate must be used if it is to react completely with 6.5 g
barium hydroxide octahydrate?
5. Coke is an impure form of carbon that is often used in the industrial production of metals from
their oxides. If a sample of coke is 95% carbon by mass, determine the mass of coke needed to
react completely with 1.0 ton of copper (II) oxide. Assume the equation is
Coke + 2 CuO  CO2 + 2 Cu
6. The compound cisplatin, Pt(NH3)2Cl2 has been studied extensively as an antitumor agent. It is
synthesized by the following reaction
K2PtCl4 + 2 NH3 Pt(NH3)2Cl2 + 2KCl
a. What mass of cisplatin can be made from 100. g of K2PtCl4 and sufficient NH3?
b. What mass of KCl is also produced?
7. Aspirin (C9H8O4) is synthesized by reacting salicylic acid (C7H6O3) with acetic anhydride
(C4H6O3).
C7H6O3 + C4H6O3  C9H8O4 + HC2H3O2
a. What mass of acetic anhydride is needed to completely consume 1.00 x 102 g salicylic
acid?
b. What is the maximum mass of aspirin (the theoretical yield) that could be produced in
this reaction?
STOICHIOMETRY: MIXED PRACTICE
Name:______________
1. Given the balanced equation Fe2O3 (s) + 2 Al (s)  2 Fe (l) + Al2O3 (s) and 4.5 g of Fe2O3
a. How many grams of iron will you end with?
b. How many moles of Al2O3 will you end with?
c. How many moles of Al do you need?
d. Draw a microscopic picture of reaction before it begins. Hint: what do you have
BEFORE the reaction happens?
e. Draw a microscopic picture of the reaction after it is finished.
2. Given the balanced equation C7H6O3 + C4H6O3  C9H8O4 + HC2H3O2 and .97 mol C7H6O3
a. How many grams of C7H6O3 did you start with?
b. How many grams of C4H6O3 did you start with?
c. How many moles of C9H8O4 did you end with?
d. How many grams of HC2H3O2 did you end with?
e. Draw a microscopic picture of the reaction.
3. Given the balanced equation Hg (l) + Br2 (l)  HgBr2 (s) and 8.56 grams of HgBr2
a. How many grams of Hg did you start with?
b. How many moles of Br2 did you start with?
c. How many moles of HgBr2 did you end with?
d. Draw a microscopic picture of the reaction.
e. Draw a macroscopic (what you would see in the lab) picture of the reaction. Make sure
to use labels and show amounts.
4.
Given the balanced equation 4 Al + 6 HCl  3 H2 + 2 AlCl3 and 5.97 g of Al
a. How many moles of aluminum did you start with?
b. How many grams of AlCl3 can you make?
c. How many moles of HCl do you need?
d. How many grams of H2 can you make?
e. How many liters of H2 can you make?
f.
Draw a microscopic picture of the reaction.
STOICHIOMETRY LAB
Name: ____________________
Pre-Lab discussion:
In a balanced chemical equation all reactants and products must be represented by symbols or
formulas. The total number of atoms of each element must be the same on each side of the equation to
satisfy the Law of Conservation of Mass.
A calculation of the formula mass of a reactant or produce enables us to convert from grams of a
particular substance taking part in a reaction to moles of that substance. The mole relationship given by
the coefficients of the balance equation then allows us to calculate how many moles of the every other
substance will take part in the reaction.
In this experiment, we will investigate the quantitative relationships in a reaction between sodium
hydrogen carbonate (NaHCO3) and hydrochloric acid (HCl). A know mass of sodium hydrogen
carbonate will be reacted with excess hydrochloric acid to produce sodium chloride, carbon dioxide and
water. Knowing the mass of NaHCO3 that reacts, we can determine form the balanced equation the mass
of sodium chloride that should be produced. We can compare this theoretical value with the actual
experimental mass of sodium chloride produced. This experiment should aid in the understanding of the
mole-mass relationships that exist in a chemical reaction and in the interpretation of a balanced chemical
equation.
Pre-Lab Questions:
1. Write a balanced chemical equation for this experiment.
2. How much sodium chloride will be produced if you used 2.50 g of sodium hydrogen carbonate.
3. What is the equation for figuring experimental error.
Purpose:
Compare the experimental mass of a produce of a chemical reaction with the mass predicted for
that product by calculation.
Materials:
Balance
Burner
Evaporating dish
Watch Glass
Microspatula
Dropper pipet
Ring Stand
Iron ring
Wire gauze
Hydrochloric acid
Sodium hydrogen carbonate
Procedure:
1. Record the mass of the evaporating dish and watch glass.
2. Measure out 2.50 g of NaHCO3 into your evaporating dish and record the
mass of the dish, glass and chemical.
3. Using a dropper pipet slowly add HCL to the NaHCO3 in the evaporating
dish a few drops at a time. Continuing adding acid until the reaction
stops. (Make sure the watch glass is on the evaporating dish. CAUTION:
HCl is a strong acid and can cause painful burns. If you get it on your
skin immediately wash the area.
4. After making sure the bubbling has stopped take the watch glass off.
5. Set up the ring stand with the wire gauze and the Bunsen burner.
6. Put the evaporating dish on the set up and heat GENTLY. If it starts to
pop or spit take the flame away and put on the watch glass.
7. When all the liquid has evaporated, turn off the flame and let the dish
cool.
8. When the evaporating dish is cool find the mass of the watch glass,
evaporating dish and product. Record this number.
Data table:
Evaporating dish and watch
glass
Evaporating dish, watch glass
and NaHCO3
Evaporating dish, watch glass
and Product
Calculations:
1. Find the mass of the NaHCO3 reactant.
2. Find the mass of the NaCl product.
Conclusions:
1. According the the balanced equation for the reaction, what is the ratio of moles of NaHCO3 to the
moles of NaCl?
2. How many moles of NaHCO3 are reacted in your experiment? How many moles of NaCl are
produce in your experiment? What is the ratio of moles of NaHCO3 to moles of NaCl produce in
your lab?
3. In your pre-lab questions you calculated the expected mass of NaCl produced. Use this to
calculate your experimental error for your experiment.
4. If all of the masses of all but one of the substances that take part in the chemical reaction are
known, explain why it is possible to determine the unknown mass of the last substance.
5. In the chemical reaction CaCO3  CaO + CO2 if 40.0 g of CaCO3 are decomposed:
a. How many grams of CaO are produced?
b. How many grams of CO2 are produced?
6. In the reaction N2 + 3H2  2 NH3 if 20.0 g of hydrogen react:
a. How many grams of ammonia are produced?
b. How many grams of nitrogen react?
STOICHIOMETRY: INQUIRY LAB
When Mrs. Adamek when into the store room she discovered that the labels had fallejn off several of the
containers. One of the containers had baking soda (NaHCO3) in it. Help Mrs. Adamek figure out which
one is the baking soda.
Pre-Lab Discussion:
In a balanced chemical equation all reactants and products must be represented by symbols or
formulas. The total number of atoms of each element must be the same on each side of the equation to
satisfy the Law of Conservation of Mass.
If you know the formula mass of a reactant or product you are able to convert from grams of a
particular substance taking part in a reaction to moles of that substance. The mole relationship given by
the coefficients of the balanced equation then allows us to calculate how many moles of the every other
substance will take part in the reaction.
In this experiment, we will compare the mass of product produced with the mass of product we
would expect if the unknown was sodium hydrogen carbonate (NaHCO3). We know that NaHCO3 will
react with hydrochloric acid to produce sodium chloride, water and carbon dioxide. We can compare this
theoretical value with the actual experimental mass of sodium chloride produced to determine which of
the unknowns is baking soda. This experiment should aid in the understanding of the mole-mass
relationships that exist in a chemical reaction and in the interpretation of a balanced chemical equation.
Pre-Lab Questions:
Answer these on a separate piece of paper.
1. Write a balanced chemical equation for this experiment.
2. How much sodium chloride will be produced if you used 2.50 g of sodium hydrogen carbonate?
3. What is the equation for figuring experimental error?
Materials:
Balance
Burner
Evaporating dish
Watch Glass
Microspatula
Dropper pipet
Ring Stand
Iron ring
Wire gauze
Hydrochloric acid
Sodium hydrogen carbonate
Procedure:
1. Record the mass of the evaporating dish and watch glass.
2. Measure out 2.50 g of unknown into your evaporating dish and record the mass of the dish, glass
and chemical.
3. Using a dropper pipet slowly add HCL to the unknown in the evaporating dish a few drops at a
time. Continuing adding acid until the reaction stops. Make sure the watch glass is on the
evaporating dish. CAUTION: HCl is a strong acid and can cause painful burns. If you get it on
your skin immediately wash the area.
4. After making sure the bubbling has stopped, take the watch glass off.
5. Set up the ring stand with the wire gauze and the Bunsen burner.
6. Put the evaporating dish on the set up and heat GENTLY. If it starts to pop or spit take the flame
away and put on the watch glass. Let it cool for a minute and then start heating again.
7. When all the liquid has evaporated, turn off the flame and let the dish cool.
8. When the evaporating dish is cool find the mass of the watch glass, evaporating dish and product.
Record this number.
9. Wash the evaporating dish and watch glass with soap and water. The product may go down the
drain. Put away the rest of your materials.
Data table:
Unknown A
Evaporating dish and watch
glass
Evaporating dish, watch glass
and Unknown A
Evaporating dish, watch glass
and Product
Unknown B
Evaporating dish and watch
glass
Evaporating dish, watch glass
and Unknown B
Evaporating dish, watch glass
and Product
Calculations:
Do these on a separate piece of paper.
1. Find the mass of each of the unknown reactants.
2. Calculate the expected (theoretical) amount of product based on the mass
of the unknown. Assume the unknown is baking soda.
3. Find the masses of each of the products.
4. Calculate the percent error for each unknown.
Conclusions:
Please answer in complete sentences on a separate piece of paper.
1. According to the balanced equation for the reaction, what is the ratio of moles of NaHCO3 to
the moles of NaCl? (2 pts)
2. Which of the unknowns is baking soda? How did you know? (6pts)
3. If your percent error was greater than zero describe some sources of error. (2 pts)
DUE Friday, April 18th
Your task:
1. You must create an original visual display (i.e. poster, pamphlet, PowerPoint, video etc) that
illustrates the concept of a mole.
2. You must create a visual/written explanation (step-by-step) of how to solve a stoichiometric mole
problem
The following must be included:
1. The definition of a mole.
2. A balanced chemical equation. You may reproduce one from a lab or text, but you must cite the
place from which you obtained it.
3. An original word problem based on the balanced equation. The problem can be a mass-mass,
mass-volume, or a volume-volume problem. You will earn more points by choosing a harder
problem. Mass-mass and mass-volume problems are typically more involved and more difficult.
Ratios of moles that are not 1:1 or 1:2 are also more difficult.
4. A step-by-step solution that is clearly set up, illustrated, and explained with captions, etc.
5. Your work must be of the highest quality. Examples of quality work will be shown.
Additional Information:
1. You may work alone or with one partner. (A video may have more than 2, but everyone must
have a CLEARLY DEFINED ROLE in producing the video). You must sign up for a group in the
next two days. If you do not sign up for a group you will have to do the project on your own.
2. All work on the project will be done outside of class. Therefore, if you work in a group, choose
people who you can get together with easily.
3. Your project is worth 40 points (as a test grade) and will be graded according to the rubric below.
10
pts
Accuracy
The written and
visual displays are
free of any math,
molar conversion
or unit errors.
9
pts
There are one or
two minor errors
that are basically
inconsequential.
8
pts
One major math,
molar conversion
or unit error may be
present, but the
majority of the
work is correct.
Several major
math, molar
conversion, or unit
errors exist.
≤7
pts
Thoroughness & Clarity
The description of how
molar conversions are
used is logical and
thorough. Complete and
logical sentences describe
the work.
The descriptions are
logical and through
enough to be
understandable by the
reader.
The descriptions are
incomplete or illogical to
the reader, but are correct
upon questioning.
Complexity
The stoichiometric
problem is a mass-mass
or volume-mass problem
with uneven rations (2:5,
3:5 3:4 etc)
Visual Display
The diagram is well
organized, neatly
displayed and
visually pleasing.
The stoichiometric
problem is a mass-mass
or volume-mass problem
with uneven rations (2:5,
3:5 3:4 etc)
The stoichiometric
problem is a mass-mass,
or volume-mass problem
with simple ratios (ex.
1:1 or 1:2)
The diagrams are
readable and
organized but not as
clearly detailed or
visually pleasing.
The diagrams are
somewhat difficult
to read or follow.
Overall format is
sloppy.
The descriptions are
incomplete and illogical.
The stoichiometric
problem is a mole-mole
or volume-volume
problem or the ratios are
simple.
Major flaws in
organization and
diagrams are
incomplete or
unclear.
STOICHIOMETRY QUIZ
Name: ____________________
Show all your work!
1.
Calculate the number of grams of H2 that can be produced from 6.80 g of aluminum. (4pts)
2 Al + 6 NaOH  2 Na3AlO3
+ 3 H2
2. How many grams of iron (III) oxide can be obtained by heating 975 g of iron (II) sulfide? (4pts)
4 FeS + 7 O2  2 Fe2O3 + 4 SO2
3. Calculate the number of grams of water that could be produced from the burning of 51 g of
ethane (C2H6). (5pts)
___ C2H6 + ___ O2  ___ CO2 + ____H2O
4. Draw a microscopic picture of the reaction in problem 1. (2pts)
(unbalanced)
STOICHIOMETRY: Scientific Notation Challenge
Name:_________________
1. How many grams of LiCl does it take to react with 1.0 g of Pb(NO3)2?
Pb(NO3)2 + 2 LiCl  2 LiNO3 + PbCl2
2. 51.0g of NH3 are reacted according to the following equation:
2 NH3  3 H2 + N2
a. How many liters of H2 are produced?
b. How many liters of N2 are produced?
c. How many molecules of N2 are produced?
3. How many molecules of H2O will be made when 5.0 x 1024 molecules of H2 are reacted with
excess O2.
4. 20 molecules of calcium chloride reacts with excess silver nitrate to create calcium nitrate and
silver chloride. How many moles of silver chloride will be produced?
5. Given HCl + NaOH  H2O + NaCl
a. How many liters of H2O gas will be made from 500 grams of HCl?
b. How many liters of H2O will be made from 500 grams of NaOH?
c. Which produces more?
6. If 10 moles of pentane, C5H12, are burned, how many molecules of CO2 will be produced?
7. If 0.2 L of methane (CH4) gas is burned. How many moles of CO2 will be produced?
8. How many grams of propane (C3H8) need to be burned if you want to produce 0.10 L of water
vapor (a gas) at STP?
9. How many grams of PCl3 will be produced when 1.43 x 1020 molecules of PCl5 are reacted?
PCl5  PCl3 + Cl
10. In the Bish process, water is created from HI and Ca(OH)2 according to the reaction below.
2 HI + Ca(OH)  CaI2 + 2H2O
The water is then used to react with CO2 to create octane and oxygen.
18 H2O + 16 CO2  2 C8H18 + 25 O2
How many molecules of octane can be created from 250 g of Ca(OH)2?
STOICHIOMETRY: Scientific Notation Practice
Name:_________________
Put all of your answers into scientific notation.
1. How many grams of PCl3 will be produced when 90 moles of PCl5 are reacted?
PCl5  PCl3 + Cl
2. How many grams of LiCl does it take to react with 1.0 g of Pb(NO3)2?
Pb(NO3)2 + 2 LiCl  2 LiNO3 + PbCl2
3. 51.0g of NH3 are reacted according to the following equation:
2 NH3  3 H2 + N2
d. How many liters of H2 are produced?
e. How many liters of N2 are produced?
f. How many molecules of N2 are produced?
4. How many liters of H2O will be made when 50 moles of H2 are reacted with excess O2?
5. 0.13 g of calcium chloride reacts with excess silver nitrate to create calcium nitrate and silver
chloride.
a. Write a balanced equation for this reaction.
b. How many moles of silver chloride will be produced?
6. Given HCl + NaOH  H2O + NaCl
a. How many liters of H2O gas will be made from 500 grams of HCl?
b. How many liters of H2O will be made from 500 grams of NaOH?
c. Which reactant produces more product?
7. If 10 moles of pentane, C5H12, are burned, how many liters of CO2 will be produced?
C5H12 + 8 O2  6 H2O + 5 CO2
8. If 0.20 L of methane (CH4) gas is burned, how many moles of CO2 will be produced?
CH4 + 2 O2  2 H2O + CO2
9. How many grams of propane (C3H8) need to be burned if you want to produce 0.1 L of water
vapor (a gas) at STP?
C3H8 + 5 O2  4 H2O + 3 CO2
10. How many grams of HI did you start with if you end with 0.1 g CaI2?
2 HI + Ca(OH)  CaI2 + 2H2O
STOICHIOMETRY: Field trip pts
Name: _____________________
1. How many grams of hydrogen are produced when 67.12 g of HCl are reacted with copper?
2 HCl + Cu  CuCl2 + H2
2. How many moles of oxygen are produce in the decomposition reaction of 145. 73 g of sodium
chlorate?
2 NaClO3  2 NaCl + 3 O2
3. 98.03 g of magnesium hydroxide are decomposed in the reaction below. How many grams of
water are produced?
Mg(OH)2  MgO + H2O
4.
How many grams of lead (II) nitrate are needed to produce 49.23 g of sodium nitrate?
Pb(NO3)2 + 2 NaCl  PbCl2 + 2 NaNO3
5. How many moles of silver are produced when 36.92 grams of copper displaces silver from silver
nitrate in the reaction below?
___Cu + ___ AgNO3  ___Ag + ____Cu(NO3)2
6. HCl is reacted with CaCO3 to produce 7.45 moles of CO2. How many grams of hydrochloric acid
were needed to produce this amount of CO2?
____HCl + ____CaCO3  ____CO2 + ____CaCl2
7. If 42.84 grams of iron are reacted with water, how many grams of iron(III) oxide are produced?
____Fe + ____H2O  ____Fe2O3 +____ H2
8. How many grams of aluminum hydroxide are produced if 165.7 g of aluminum sulfate are reacted
with calcium hydroxide.
____ Al2(SO4)3 + ____ Ca(OH)2  ____Al(OH)3 + ____CaSO4
9. In this synthesis reaction below, 29.48 g of fluorine are reacted with excess sodium. How many
moles of NaF are produced?
___ Na + ___ F2  ____ NaF
10. If 8.4 moles of aluminum bromide is reacted with fluorine, how many grams of bromine are
produced?
___F2 +___ AlBr3  ____Br2 + ____AlF3