CHM1032C Grading Outline
Chapter 6 Chemical Reactions:
Moles and Mass Relationships
A._____(02) Molecular Mass CalculationSection6.1 Answers a
B._____(02) Mole
Calculations ISections 6.2 Answers
bcd
B1._____(02) Mole Calculations
IISections 6.2 Answers
bcd
C._____(02) Percentage Composition
CalculationLecture Answers
bcd
D._____(02) Empirical Formula
Calc. from % CompLecture Answers
bcd
D1._____(02) Empirical Formula
Calc. from Lab DataLecture Answers bcd
I.______(02) MoleMole Problems Section 6.3 Answers ij
J._____ (03) MassMass Stoichiometric ProblemsSection 6.4 Answers ij
K._____(03) Excess/Limiting Reagent ProblemsSection 6.5 Answers kl
L._____(02) Percent YieldSection
6.5 Answers
______(14) Chapter 6 Total
Chapter 6: Chemical Reactions:
Mole and Mass Relationships Table Contents
6.1 The Mole and Avogadro’s Number M5B
6.2 Gram—Mole ConversionsM5A/B1
6.3 Mole Relationships and Chemical Equations M5I
6.4 Mass Relationships and Chemical EquationsM5J
6.5 Limiting Reagent and Percent Yield M5K
Chapters
3 through 7 Concept Map:
Module
FivePart A: Molecular Mass Calculation 2 points
1 mole of atoms = 6.023 x 10^{23} atoms. See “What is a mole?” Lab
Analogies.
The atomic mass of any substance expressed in grams is the molar mass
(MM) of that substance.
•
The
atomic mass of carbon is 12.01 amu per atom.
•
Therefore,
the molar mass of carbon is 12.01 g/mol .
•
Since
nitrogen occurs naturally as a diatomic, N_{2}, the molar mass of
nitrogen gas is two times 14.01
g or 28.02 g/mol.
Calculating
Molar Mass
•
The
molar mass of a substance is the sum of the molar masses of each element.
•
What
is the molar mass of copper(II) nitrite, Cu(NO_{2})_{2}?
•
The
sum of the atomic masses is as follows:
63.55 + 2(14.01 + 16.00 +
16.00) =
63.55 + 2(46.01) = 155.57 amu per molecule
•
The
molar mass for Cu(NO_{2})_{2} is
155.57 g/mol.
Molar Mass Connects Moles to Grams & Vice versa:
Module
FivePart A: Molecular Mass Calculation 2 points
Homework #1:
Using a periodic
chart calculate the molar mass of the following:
1. Calculate the molecular
mass of Acetic Acid, HC_{2}H_{3}O_{2}.
2. Calculate the
formula unit mass of Ammonium Chromate,
(NH_{4})_{2}CrO_{4} .
3. Calculate the
molecular mass of glucose,
C_{6}H_{12}O_{6}.
Reference:
McMurry Section 6.2 Try problems: 6.23,
6.24, 6.27, 6.30, 6.31, 6.32, 6.33, 6.34, 6.35
Corwin
Section 8.3 Additional Problems: Corwin #13#16 Pages 244245
Hein:
Section 7.2: Example 7.7; 7.8 End of Chapter #1#2 Page 139
Interactive Online ChemiCalc(Molar Mass & %
Composition):
http://people.emich.edu/bramsay1/cccrelease/chem.html
Chapter
6 Sections 6.36.4Lecture
From Another Text:
Chapter 6: Part
I MoleMole
Stoichiometry 2 points
Homework #1: Tungsten occurs in the important mineral sheelite (Calcium tungstate),
which is converted to tungstic acid. Tungsten is then extracted from tungstic acid by the following (unbalanced) reaction:
H_{2}
+ H_{2}WO_{4} à W +
H_{2}O (Unbalanced)
How moles of hydrogen is needed to prepare 6 moles of elemental
tungsten?
Homework #2: Phosphoric acid can be made by the following (unbalanced) reaction:
H_{2}O + P_{4}O_{10} à H_{3}PO_{4 }(unbalanced)
How many moles of
Phosphoric acid can be prepared from the combination of 5 moles of Tetraphosphorus decoxide with
excess water?
References:
See
McMurry: Section 6.36.4; See Worked Example 6.5; Try Problem6.8 page 166
Try
End of Chapter: Problems 6.39, 6.40
See
Hein Worked Examples: 9.29.5 pages
170173
Try Practice 9.2 and 9.3 page 173
Also try Problems 9101112 page 184
Corwin
7^{th} Reference: Section 9.19.2
Corwin 1025: see worked Examples 9.2 page 253
additional Suggested Problems: Page 2734 #7#12
Chapter
6 Section J: MassMass Stoichiometry 3 Points
Use this concept map for Part J MassMass Problems:
Step 1:
A MassMass Worked Example From Another
book:
Using all three steps:
The Solution to: __?____g Hg = 1.25g 1.25 g HgO
Another MassMass Worked Example from
Another book
Still Another Worked Example from Another
book:
From book to book, the three steps are illustrated:
Chapter
6 Section J: MassMass Stoichiometry 3 Points
Homework
#3: Toluene and nitric acid
are used in the production of trinitrotoluene (TNT), an explosive:
C_{7}H_{8} +
HNO_{3} à C_{7}H_{5}N_{3}O_{6} +
H_{2}O (Unbalanced)
Calculate the mass
of TNT that can be made from 192 g of C_{7}H_{8} (toluene).
(You must use dimensional analysis to
show your work!)
Homework
#4: What
mass of carbon dioxide is produced from the combustion of 176 grams of propane gas , C_{3}H_{8}
, in excess oxygen gas, O_{2}.
Water is the only other product.
(You must use
dimensional analysis to show your work!)
Write the Balanced Reaction:
Homework
#5:
Write the Balanced Reaction:
Engine
knocking is an unwanted process that can occur during combustion in internal combustion engines. Graham Edgar in 1926 added
different amounts of nheptane C_{7}H_{14})and
2,2,4trimethylpentane to gasoline, and discovered that the knocking stopped
when 2,2,4trimethylpentane was added. This was the origin of the octane
rating scale.^{[5]}
Test motors, using 2,2,4trimethylpentane gave a
certain performance which was standardized as 100 octane. The same test motors,
run in the same fashion, using heptane, gave a
performance which was standardized as 0 octane. All
other compounds and blends of compounds then were graded against these two
standards and assigned octane numbers.
Gasoline Molecule 

References:
McMurry:
See Worked examples 6.6 and 6.7 page 168Try Problem 6.10 page 169.
Also try end of chapter problems: 6.39 to 6.51 pages 175176
See Hein Worked Examples 9.89.9 pages 174175
Try Practice 9.6 and 9.7 page 176
Also try End of Capter Problems 1318 page 184
see Corwin worked Examples 9.4 p256
and 9.5 p257
Try end of Chapter additional Suggested Corwin Problems: Page 274 #19#27
Part K
ExcessLimiting Reagent Problem 3
points
Sample Limiting Reagent Problem (Chapter
6 Part K)
Some books teach you to determine
which reagent is the limit first, then do the standard
gramgram problem
Either works, but I prefer the method above
(working two separate
gramgram problems and which produces the lowest number that is the correct
sequence and answer.
Reference:
McMurry: Chapter 6 Section 6.5
See Worked Examples
6.9, 6.10, and 6.11 which also includes Percent yield (Chapter 6 Part L) pages
170171; Try Problems 6.12, 6.13, and 6.14 page 171
Corwin: Review Sections 9.7 and 9.8
see worked Examples 9.10 p267
additional Suggested Problems: p276 #59#74
Hein: Chapter 9 Section 9.5
see worked examples 9.11, 9.12, 9.13, 9.14 pages 178181
Try problem 9.9 page 180; 9.10 page 181
End of chapter: Try