Download unit 7 hw packet File - District 196 e

Chemistry
Name ________________________
Unit #7 Plan – Stoichiometry (Extended Mole Train)
I)
Assignments / Handouts
A)
Mole ratios
B)
Stoichiometry – extended mole train
C)
Stoichiometry chart style
D)
Riding the locoMOLEtive – more stoichiometry
E)
Excess / Limiting Reactant notes
F)
Excess / Limiting Reactant ws
G)
Aluminum / copper II sulfate lab
H)
Limiting reactant lab
I)
More TBA
(required – pg 3-4)
(required – pg 5-6)
(required – pg 7-8)
(required – pg 9-10)
(required – pg 11-12)
(required – pg 13-14)
II)
Text Support Chapter 11 (pg 326-359)
On-Line Text: www.lab-aids.com
Username:
evhs1
Password:
smeyer
(Log in as student in upper right corner. This is a common username and
password for all my chemistry students.)
III)
Learning Targets (I can …)
A)
Use mole ratios to compare relative amounts of reactants and products in a
balanced equation.
B)
Perform problem solving conversions for moles, grams, atoms and
molecules within a balanced equation (operating the extended mole train)
using each of the following methods:
 Dimensional analysis
 Chart style
C)
Operate the extended mole train in problems with excess and limiting
reactants
 Identify limiting reactants and excess reactants.
 Determine amounts of excess reactants left over.
 Determine amounts of products formed
D)
Determine % yield from experimental data.
E)
Identify and analyze current issues involving stoichiometry.
IV)
V)
Tentative Schedule
Mon
Tue
Wed
Thu
Fri
1/28
1/29
1/30
1/31
2/1
Mole review
Mole ratios
Stoichiometry – extended mole train
Extended mole train
Quiz (emphasis on mole review and mole ratios)
Mon
Tue
2/4
2/5
Wed
Thu
2/6
2/7
Stoichiometry – chart style
Stoichiometry practice
Prep expt #7 (aluminum / copper sulfate lab)
Expt #7
Quiz (emphasis on stoichiometry)
Mon
Tue
Wed
Thu
2/11
2/12
2/13
2/14
Fri
2/15
Tue
Wed
2/19
2/20
XS / LR notes
XS / LR ws
Prep XS/LR lab
Quiz (emphasis on XS/LR)
XS/LR lab
XS / LR lab wrap-up
Review
Unit #7 Exam
Unit #7 HW packet due
On-line support
 Mr. Guch’s website
http://misterguch.brinkster.net/explains2.html (balancing equations, writing word equat,
types of reactions)
This website will help you out in your quest to understand chemistry. Explanations are at
the introductory level and give some detail --- but not too much. Even the humor is well
above average. You need to check this out.
 ChemTeam
www.chemteam.info (chemical equations and reaction types)
This website may help you in your quest to understand chemistry. Explanations can get
quite involved – depending on the topic. It may be helpful at the introductory level. It will
be especially helpful if you are looking for extra detail.
Introduction of Stoichiometry: mole ratio
Name ________________________
Mole ratio (determined by comparing coefficients of reactants and/or products
in a balanced equation)
1.
Given this equation: N2 + 3 O2 ---> 2 NO3, write the following mole ratios:
a) N2 / O2
___________
b) N2 / NO3 ___________
c) O2 / NO3 ___________
2.
Given the following equation: 8 H2 + S8 ---> 8 H2S, write the following mole
ratios:
a) H2 / H2S
___________
b) H2 / S8
___________
c) H2S / S8
___________
3.
Answer the following questions for this equation: 2 H2 + O2 ---> 2 H2O
a) What is the H2 / H2O mole ratio?
b) Suppose you had 20 moles of H2 on hand and plenty of O2, how many
moles of H2O could you make?
c) What is the O2 / H2O mole ratio?
d) Suppose you had 20 moles of O2 and enough H2, how many moles of
H2O could you make?
4.
Use this equation: N2 + 3 H2 ---> 2 NH3, for the following problems
a) If you used 1 mole of N2, how many moles of NH3 could be produced?
b) If 10 moles of NH3 were produced, how many moles of N2 would be
required?
c) If 3.00 moles of H2 were used, how many moles of NH3 would be made?
d) If 0.600 moles of NH3 were produced, how many moles of H2 are
required?
5.
The following equation represents a laboratory preparation for oxygen gas:
2KClO3(s) + heat  2 KCl(s) + 3O2(g)
How many moles of O2 form if 3.0 mol of KClO3 are totally consumed?
6.
Given the following equation:
H2(g) + F2(g) 
a.
How many moles of H2 gas are consumed as 5 mol of fluorine gas react?
7.
b.
How many moles of HF gas are produced as 5 mol of fluorine gas react?
c.
How many grams of HF gas are produced as 5 mol of fluorine gas react?
Water can be made to decompose into its elements by using electricity according
to the following equation:
2H20(l) + electrical energy 
2(g) + O2(g)
a.
How many moles of O2 are produced if 5.0 mol of water decompose?
b.
8.
What mass of O2 is produced if 5.0 mole of water decompose?
Sodium metal reacts with water to produce sodium hydroxide and hydrogen gas
according to the following equation:
2Na(s) + 2H2O(l) 
2(g)
a.
How many moles of sodium are consumed if 92 grams of sodium metal
react with excess water?
c.
How many moles of hydrogen gas are produced if 92 grams of sodium
metal react with excess water?
Stoichiometry (Extended Mole Train)
Name________________________
Stoichiometry - Determining relationships between quantities of substances in a
chemical reaction.
Steps for solving stoichiometry problems:
1.
Balance chemical equation.
2.
Identify what you know (starting point).
3.
Identify what you are trying to find (ending point).
4.
Use extended mole to make appropriate calculations.
5.
Recheck answer. It should “make sense”.
Directions: Answer the following questions. Show work and proper units.
1.
32 grams of methane (CH4) burn in excess oxygen gas to produce carbon
dioxide and water vapor.
___ CH4
2.
+
___ O2

___ CO2
+
___ H2O
A.
B.
Balance the equation.
How many grams of oxygen (O2) gas are consumed?
C.
How many grams of CO2 form?
D.
How many moles of water form?
What mass of oxygen is needed to make 180 grams of P4O10 by burning
phosphorus?
4P
+
5 O2

1 P4O10
3.
Magnesium metal burns in excess oxygen to form 200 grams of MgO.
___ Mg
4.
___ MgO
Balance the equation.
What mass of Mg burned?
C.
How many moles of O2 reacted?
100 grams of chromium (III) fluoride decomposes.

2 Cr
+
3 F2
A.
What mass of Cr forms?
B.
How many moles of F2 forms?
C.
How many molecules of F2 forms?
What mass of chlorine gas is needed to completely react with 15.9 grams of
iron (III) iodide? (Balance the equation.)
___ FeI3
6.

___ O2
A.
B.
2 CrF3
5.
+
+
___ Cl2

___ FeCl3
+
___ I2
What mass of nitrogen (N2) gas is consumed in the production of 240 grams
of ammonia (NH3) gas? (Balance the equation)
___ N2
+
___ H2

___ NH3
Stoichiometry Chart Style
Directions: For each question, complete the chemical equation and balance it.
Then complete the chart.
1. 95.4 g of Cu (II) reacts with AgNO3 in a single displacement reaction.
Mass (g)
___ Cu
95.4
+
___ AgNO3

Molar Mass
(g/mol)
Moles
2. 125 g of HCl reacts with Zn in a single displacement reaction.
Mass (g)
___ HCl
125
+
___ Zn

Molar Mass
(g/mol)
Moles
3. Magnesium hydroxide decomposes into magnesium oxide and 45.0 g of
water.

Mass (g)
Molar Mass
(g/mol)
Moles
4. The double displacement reaction between lead (II) nitrate and sodium
iodide produces sodium nitrate and 69.2 g of lead (II) iodide.

Mass (g)
Molar Mass
(g/mol)
Moles
Stoichiometry – Chart Style
Name ___________________________
Directions: Balance each equation. Complete each chart.
___ Na +
Mass
(g)
Molar Mass
(g/mol)
# of Moles
___ NaCl
1.5
___ Al
Mass
(g)
Molar Mass
(g/mol)
# of Moles
___ Cu +
138
Mass
(g)
Molar Mass
(g/mol)
# of Moles
Mass
(g)
Molar Mass
(g/mol)
# of Moles
___ CuCl2 
+
___ Cu(NO3)2 
81
1.5
___ Cu + ___ Al(NO3)3
Riding the LocoMOLEtive
Name_________________________
Steps for solving stoichiometry problems:
1. Write a balanced chemical equation.
2. Identify what you know (starting point).
3. Identify what you are trying to find (ending point).
4. Use extended mole to make appropriate calculations.
5. Recheck answer. It should “make sense”.
Directions: Solve the following problems. The equations given are not balanced. Balance
them first. Show work and proper units.
1. 66 grams of propane (C3H8) burn in excess oxygen. What mass of carbon dioxide
is produced?
2. 97.2 grams of magnesium metal burns completely in air to form magnesium
oxide. What mass of oxygen is consumed?
3. How many moles of hydrogen (H2) are consumed in the production of 526 grams
of ammonia (NH3) gas?
___ N2
+
___ H2

___ NH3
4. If 20.0 grams of zinc react with excess hydrochloric acid (hydrogen chloride) in a
single displacement reaction, how many grams of zinc chloride are produced?
5. How many grams of chlorine gas must be reacted with excess sodium iodide to
make 10.0 grams of sodium chloride in a single displacement reaction?
6. How many grams of oxygen are produced in the decomposition of 5.00 moles of
potassium chlorate?
___KClO3

___ KCl
+
___ O2
7. How many atoms of copper are required to displace 4.00 grams of silver nitrate
which are dissolved in water?
8. If excess ammonium sulfate reacts with 20.0 grams of calcium hydroxide, how
many moles of ammonia (NH3) are produced?
___ (NH4)2SO4 + ___ Ca(OH)2
9.
 ___CaSO4 + ___ NH3 + ___ H2O
132 grams of sodium reacts vigorously with excess water (hydrogen hydroxide) in
a single displacement reactant. What volume of hydrogen gas is produced? (Hint:
Write the balanced chemical equation for the reaction. Then use the mole train to
solve the problem.)
Excess / Limiting Reactant “Notes”
Name ____________________________
Limiting Reactant (LR) – reactant that runs out first, limiting amount of product
formed.
Excess Reactant (XS) – reactant that is not completely used up; the reactant that is left
over.
1.
50 ice cream scoops “react with” 20 cones to produce ice cream treats
according to the following equation:
2 scoops
2.
+
1 cone

1 treat
A.
What is the limiting reactant?
B.
What reactant is in excess? How much of it is left over?
C.
How many treats are produced?
50 moles of hydrogen gas react with 20 moles of oxygen gas to produce water
vapor according to the following equation:
2 H2
+
O2

2 H2O
A.
What is the limiting reactant?
B.
What reactant is in excess? How many moles of it are left over?
C.
What mass of water vapor is produced?
3.
50 ice cream scoops “react with” 30 cones to produce ice cream treats
according to the following equation:
2 scoops
4.
+
1 cone

1 treat
A.
What is the limiting reactant?
B.
What reactant is in excess? How much of it is left over?
C.
How many treats are produced?
100 grams of hydrogen gas react with 960 grams of oxygen gas to produce
water vapor according to the following equation:
2 H2
+
O2

2 H2O
A.
What is the limiting reactant?
B.
What reactant is in excess? How many moles of it are left over?
C.
What mass of water vapor is produced?
Excess / Limiting Reactant “Worksheet” Name ____________________________
Directions: Balance equations. Show work and appropriate units.
1.
160 grams of hydrogen gas react with 960 grams of oxygen gas to produce
water vapor according to the following equation:
2 H2
2.
+
O2

2 H2O
A.
What is the limiting reactant?
B.
What reactant is in excess? What mass of it is left over?
C.
What mass of water vapor is produced?
132 grams of propane (C3H8) gas react with 384 grams of oxygen gas to
produce water vapor and carbon dioxide according to the following equation:
___ C3H8
+
___ O2

___ CO2
+
___ H2O
A.
B.
Balance the equation.
What is the limiting reactant?
C.
What reactant is in excess? How many moles of it are left over?
D.
What mass of carbon dioxide is produced?
3.
What mass of sodium sulfate is produced if 24.0 grams of sodium hydroxide
reacts with 39.2 grams of sulfuric acid according to the following equation:
___ NaOH
4.
___ H2SO4

___ Na2SO4
+
___ H2O
What mass of sodium is produced if 15 grams of sodium phosphide reacts
with 39 grams of potassium according to the following equation:
___ Na3P
5.
+
+
___ K

___ K3P
+
___ Na
24.3 grams of aluminum foil react with 144 grams of cupric sulfate to produce
aluminum sulfate and copper according to the following equation:
___ Al
+
___ CuSO4

___ Al2(SO4)3
+
___ Cu
A.
B.
Balance the equation.
What is the limiting reactant?
C.
What reactant is in excess? How many moles of it are left over?
D.
What mass of Cu is produced
Chapter 11 Book Assignment (p. 326-359)
1. Water is split by an electric current to give the following chemical reaction
2 H2O(liq)  2 H2(g) + O2(g)
The volume of H2 gas produced is 2 times the volume of O2 gas produced.
Are the moles of H2 gas produced also 2 times the moles of O2 produced?
Explain.
2. Propane (C3H8) burns to give the following chemical equation
1 C3H8 + 5 O2  3 CO2 + 4 H2O
Refer to the reaction above. Indicate whether each statement below is true or
false.
o The coefficients (1, 5, 3, 4) compare number of moles.
o The coefficients (1, 5, 3, 4) compare number of molecules.
o The coefficients (1, 5, 3, 4) compare number of grams.
3. Refer to the reaction in #2 above. Indicate whether each statement below is true
or false.
o Moles are conserved.
o Molecules are conserved.
o Atoms are conserved.
o Mass is conserved
4. Define stoichiometry
5. Does a “stoichiometric equivalent” compare moles or does it compare grams in
a balanced chemical equation?
6. Define mole ratio.
7. Refer to the reaction in #2 above. If 2 moles of propane are completely burned,
o How many moles of O2 are consumed?
o How many moles of CO2 are produced?
o How many moles of H2O are produced?
8. What is the formula for percent yield.
9. What is meant by the “theoretical yield”?
10. What is meant by the “actual yield”?
11. Calculate percent yield if the theoretical yield is 17.10 grams and the actual yield
is 12.5 grams. Show work.
12. Explain what causes the actual yield to be less than the theoretical yield? (There
are many plausible answers.)
13. Define limiting reactant?
14. Define excess reactant?
15. Does the limiting reactant or excess reactant determine the amount of product
formed? Explain.
16. When identifying the limiting reactant, what must be compared (grams or
moles)? – Explain.
17. True or False --- stoichiometric proportions are based on mole ratios
18. True or False --- stoichiometric proportions are based on mass (gram) ratios
19. Explain how to calculate the amount of excess reactant left over in a reaction.
(Hint: see page 356 or the back of your mole train guide)
20. CO2 is released into the atmosphere through the burning of fossil fuel (coal,
natural gas, gasoline, etc) List 2 ways the environment absorbs CO2? (Hint: see
pages 358-359)