CEM 141 Chapter 3 Test Exam|| Most Recent 2025/2026 Actual
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Difference between Covalent Bonds and Molecular Interactions
- ANSWER-1. Covalent bonds are within molecules, very
strong, hard to predict strength, and are present only when
atomic orbitals interact constructively
2. Molecular Interactions are between molecules, relatively
weak, caused by fluctuating electron distributions, and
increase with the size of the electron cloud
Explain how bonding leads to high MP in iron (Fe) - ANSWER-
1. bonding in Fe
is a like a
network
a. valence electrons are delocalized and hold the core
electrons together
b. to break this you would need a lot of energy, which
explains the high MP
Bonding in Carbon Compounds - ANSWER-1. carbon
forms four bonds
a. forms bonds to C, H, O, N, S, P, etc. (including
halogens)
,2. properties of compounds are emergent (not just sum of
elements involved)
Characteristics of Methane (CH4) - ANSWER-1. Contains
4 C-H bonds
a. equidistant from each
other
b. identical (because of sp^3 hybridization on
the carbon)
Rules for drawing Lewis Structure - ANSWER-1. calculate total
number of valence electrons
a. use group number for each element
b. for cations: remove n electrons
c. for anions: add n electrons
2. write skeleton structure (look at way formula is written)
a. use the valence (valence= 8- # of valence electrons)
3. make 2 electrons for each bond
4. make sure each atom (except H and B) has 8 electrons by
adding lone pairs
5. if there are not enough electrons form multiple bonds
Which will have a higher BP: CH4 or C2H6? - ANSWER-C2H6
because the molecule is bigger and therefore has more LDFs,
requiring more energy to break them
What info is missing from a Lewis Structure? - ANSWER-3D
What is the same in isomers? - ANSWER-1. chemical formula
, 2. number of each type of atoms
3. look for the longest chain and where the double bonds and
triple bond is located is how you determine if two molecules
are isomers
What is different in isomers? - ANSWER-1. connectivity
between atoms
2. different
properties
How many different isomers can you draw for the formula
C5H12? (different
arrangement of atoms) - ANSWER-3 (shortest C chain you
could make was 3)
What is the generic formula for a hydrocarbon containing "n"
carbon atoms? -
ANSWER-1.
CnH2n+2
a. can only use formula if there are no double bonds, triple
bonds, or rings
b. Ex. What is the formula for a linear hydrocarbon
with 7 C atoms?
i.
C7H16
What is causing the attraction between two H atoms? (covalent
bond) - ANSWER-The nuclei of one atom pulling on the
electrons of the other. This results in a "tug of war" over the
Complete Real Exam Questions And Verified Answers | 100%
Correct Answers Graded A+ / Guaranteed Success!! Newest
Exam / Just Released!!!
Difference between Covalent Bonds and Molecular Interactions
- ANSWER-1. Covalent bonds are within molecules, very
strong, hard to predict strength, and are present only when
atomic orbitals interact constructively
2. Molecular Interactions are between molecules, relatively
weak, caused by fluctuating electron distributions, and
increase with the size of the electron cloud
Explain how bonding leads to high MP in iron (Fe) - ANSWER-
1. bonding in Fe
is a like a
network
a. valence electrons are delocalized and hold the core
electrons together
b. to break this you would need a lot of energy, which
explains the high MP
Bonding in Carbon Compounds - ANSWER-1. carbon
forms four bonds
a. forms bonds to C, H, O, N, S, P, etc. (including
halogens)
,2. properties of compounds are emergent (not just sum of
elements involved)
Characteristics of Methane (CH4) - ANSWER-1. Contains
4 C-H bonds
a. equidistant from each
other
b. identical (because of sp^3 hybridization on
the carbon)
Rules for drawing Lewis Structure - ANSWER-1. calculate total
number of valence electrons
a. use group number for each element
b. for cations: remove n electrons
c. for anions: add n electrons
2. write skeleton structure (look at way formula is written)
a. use the valence (valence= 8- # of valence electrons)
3. make 2 electrons for each bond
4. make sure each atom (except H and B) has 8 electrons by
adding lone pairs
5. if there are not enough electrons form multiple bonds
Which will have a higher BP: CH4 or C2H6? - ANSWER-C2H6
because the molecule is bigger and therefore has more LDFs,
requiring more energy to break them
What info is missing from a Lewis Structure? - ANSWER-3D
What is the same in isomers? - ANSWER-1. chemical formula
, 2. number of each type of atoms
3. look for the longest chain and where the double bonds and
triple bond is located is how you determine if two molecules
are isomers
What is different in isomers? - ANSWER-1. connectivity
between atoms
2. different
properties
How many different isomers can you draw for the formula
C5H12? (different
arrangement of atoms) - ANSWER-3 (shortest C chain you
could make was 3)
What is the generic formula for a hydrocarbon containing "n"
carbon atoms? -
ANSWER-1.
CnH2n+2
a. can only use formula if there are no double bonds, triple
bonds, or rings
b. Ex. What is the formula for a linear hydrocarbon
with 7 C atoms?
i.
C7H16
What is causing the attraction between two H atoms? (covalent
bond) - ANSWER-The nuclei of one atom pulling on the
electrons of the other. This results in a "tug of war" over the
