Download unit 7a homework packet - District 196 e

Honors Chemistry
I)
Unit #7 Plan – Stoichiometry (Extended Mole Train)
Assignments / Handouts
A)
Mole review
B)
Mole ratios
C)
Stoichiometry – extended mole train
D)
Stoichiometry chart style
E)
Riding the locoMOLEtive – more stoichiometry
F)
Chapter 12 text assignment
G)
Stoichiometry lab
H)
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 12)
 Section 12-1 pg 382-389
intro to stoichiometry
 Section 12-2 pg 390-399
mole ratios --- extending the mole train
 Section 12-3 pg 400-404
limiting and excess reagents
 Section 12-3 pg 404-408
percent yield
Pearson Chemistry On-Line Text is now available at www.successnetplus.com
(Log in as returning user near the upper right corner. Following is the common username and
password for all honors chemistry students.)
Username:
yetties
Password:
sasquatch1 (the last symbol is the number “one” and not letter “l”)
Then choose from the following:
e-text (for on-line text)
practice (for support materials)
Standardized Test Prep Key for chapter 12 on page 417
1-A
2-C
3-B
4--- 3 T2 + Q2 = 2 T3Q
5--- T2 6--- true/correct
7--- true/correct (if no impurities) but false (if impurities)
8--- true/correct
9-false 10-false
Science Geek Website at www.sciencegeek.net (choose chemistry homepage from menu on left)
Interactive practice activities
Unit #4 – Conservation of Matter (bullet points 10-13)
Stoichiometry Practice Problems
Moles to moles; grams to grams
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)
Tentative Schedule
Mon
Tue
Wed
Thu
Fri
1/4
1/5
1/6
1/7
1/8
Chemical reactions lab quiz
Chemical reactions lab quiz; Mole review (on own)
Mole ratios
Stoichiometry - extended mole train (dimensional analysis)
Stoichiometry – chart style; riding the locoMOLEtive
Mon
Tue
1/11
1/12
Wed
Thu
1/13
1/14
Intro to Qualitative Analysis Lab (prep)
Unit #7 exam
Unit #7 HW packet due
Qualitative Analysis Lab
Qualitative Analysis Lab
Tue
Wed
1/19
1/20
Thu
1/21
Qualitative Analysis Lab
Qualitative Analysis Lab
Written lab quiz
Qualitative Analysis Lab
Mon
Tue
Wed
Thu
Fri
1/25
1/26
1/27
1/28
1/29
Qualitative Analysis Lab Due
Final exam prep
Final Exam
Final Exam
TBA
V)
On-line support
 Mr. Guch’s website
http://misterguch.brinkster.net/explains2.html (stoichiometry explained)
This website may 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 may be above
average.
 ChemTeam
www.chemteam.info (stoichiometry)
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.
Mole Review (Chapter 10)
Name _______________________
A __________ is an animal that burrows in the ground.
A __________ is the spot on your chin that you gotta shave around.
A __________ is a number (can’t you see) that we use in chemistry.
There are __________ of anything in a dozen of that thing.
There are ____________________ of anything in a mole of that thing.
Avogadro’s number is _______________________.
A mole of any gas at STP (standard temperature pressure) has a
volume of __________ liters.
8. The abbreviation for “mole” is _______________.
9. The mass of 1 mole of an element is equal to the __________________
on the periodic table.
One atom of Mg has a mass of 24.31 amu.
One mole of Mg atoms has a mass of 24.31 grams.
The molar mass of Mg is 24.31 grams/mol.
10. You can find the molar mass of a compound by adding all the
masses of each element in the compound.
Example: H2O:
2 Hydrogen atoms (2 x 1.0 g/mol) = 2.0
1 Oxygen atom (1 x 16.0 g/mol) = +16.0
18.0 g/mol of water
1.
2.
3.
4.
5.
6.
7.
Find the molar mass of the following elements / compounds (nearest 0.1g)
Substance
Molar Mass
Substance
Formula
Molar Mass
Neon
Tin
Iron
Magnesium
Potassium
Nitrogen gas
(N2)
Oxygen gas
(O2)
Chlorine gas
(Cl2)
Carbon
Dioxide
Carbon
tetrachloride
Ammonium
sulfide
Sulfur
Dioxide
Sodium
Chloride
Silver
Nitrate
Sugar
(C6H12O6)
Sodium
bicarbonate
Answer questions 1-9 below.
Show work, appropriate units and significant figures.
1.
What is the mass of 4.0 moles of CO2 molecules?
2.
How many molecules of CO2 are in 4.0 moles of CO2?
3.
How many moles of calcium are in 256 grams of calcium?
4.
Determine the mass of 3.50 moles of magnesium nitrate.
5.
Determine the mass of 20.0 moles of gold.
6.
Determine the mass of 9.2 x 1022 atoms of copper.
7.
How many molecules of NaCl are in 65.5 grams of NaCl?
8.
How many moles of water are in 45 grams of water?
9.
How many moles of silver nitrate are in 48 grams of silver nitrate?
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)  2HF(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  2H2(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)  2NaOH(aq) + H2(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 train 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 train to make appropriate calculations.
5. Recheck answer. It should “make sense”.
Directions: Solve the following problems. Start by writing the balanced equation for
each reaction. 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? (Assume one product is cupric nitrate.)
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
 ___CaSO4 + ___ NH3 + ___ H2O
9. 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.)
Chapter 12 Book Assignment (p. 382-408)
1 – What is stoichiometry?
2 – If a recipe is “doubled”, does the ratio between ingredients change? Explain.
3 – If a chemical equation is “doubled”, does the ratio between reactants and/or
products change? Explain.
4 – What is a mole ratio?
5 – A recipe to make a giant cookie calls for twice as many eggs as cups of flour and
half as many cups of sugar as cups of flour.
A- Write an equation for the production of the giant cookie.
B- What are the following ingredient ratios in the production of the giant
cookie?

Number of eggs to cups of sugar

Cups of flour to cups of sugar

Cups of flour to number of eggs
6 – In a balanced chemical equation, which of the following are always true?
 Sum of reactant coefficients = sum of product coefficients
 Sum of reactant atoms of any element = sum of product elements of the
same element
 Mass of reactant atoms = mass of product atoms
 Volume of reactants = volume of products
7 – Verify that mass is conserved in the following chemical reaction
2 moles of hydrogen gas + 1 mole of oxygen gas  2 moles of water vapor
8 – What is the volume of 1.00 moles of any gas at STP?
9 – What is the volume of 5.00 moles of any gas at STP?
10 – What are the conditions for temperature and pressure at STP?
11 – Why is it important to use dimensional analysis when performing stoichiometry
calculations?
12 – What mass of sodium metal is needed to produce 50.0 liters of nitrogen gas for a
standard car air bag. Assume STP. Show work. Hint – see page 397.
13 – Define excess reagent (reactant).
14 - Define limiting reagent (reactant).
15 – Does the excess reactant or limiting reactant determine the amount of product in
any chemical reaction? Explain.
16 -
2 Cu + S  Cu2S
If 1.5 mol of copper are combined with 1.0 mol of sulfur; the limiting reactant is
the copper even though there are more moles of copper. Explain.
17 – Define theoretical yield
18 - Define actual yield
19 – What is the formula for percent yield?
20 – 24.3 grams of calcium carbonate is heated to produce carbon dioxide gas (not
measured) and 10.0 grams of calcium oxide. What is the % yield for this reaction? Show
work.
21 – Explain why a reaction might give less than a 100% yield.
22 - Explain why a reaction might give greater than a 100% yield.
LocoMOLEtive --- Scrambled Answers
 does not include units
 includes significant figures
46.4
6.07
7.08 x 1021
64.2
0.540
2.0 x 102
64.0
41.7
2.40 x 102