CEM 141 EXAM 3 2026 INTRODUCTORY
CHEMISTRY ASSESSMENT QUESTIONS
SOLUTIONS GRADED A+
◉ Binding in Diamond.
Answer: Each carbon forms 4 bonds to 4 identical carbons;
tetrahedral; sp3
◉ Valence Bond Theory.
Answer: The idea that covalent bonds are formed when orbitals of
different atoms overlap.
◉ T/F: Electrons are localized in molecular orbital..
Answer: False
◉ T/F: Electrons are localized in Valence Bond..
Answer: True
◉ T/F: When the hybrid orbitals combine, there is a large gap
between the bonding and anti bonding orbitals..
Answer: True
, ◉ Bonding in Tetrahedral C results in......
Answer: Sigma bonds.
◉ Bonding in Graphite.
Answer: 3 sp2 orbitals; trigonal planar; sigma bond
◉ Is graphite localized ?.
Answer: Has a localized sigma bond network but has a delocalized pi
network over the whole sheet of atoms.
◉ What does a larger electron cloud provide?.
Answer: Higher boiling point and more surface area to overcome
LDF's.
◉ Can you rotate around a double bond?.
Answer: No - bonds will break.
◉ What is a sigma bond?.
Answer: Single covalent bond (sp2-sp2 overlap).
◉ What is a Pi Bond?.
CHEMISTRY ASSESSMENT QUESTIONS
SOLUTIONS GRADED A+
◉ Binding in Diamond.
Answer: Each carbon forms 4 bonds to 4 identical carbons;
tetrahedral; sp3
◉ Valence Bond Theory.
Answer: The idea that covalent bonds are formed when orbitals of
different atoms overlap.
◉ T/F: Electrons are localized in molecular orbital..
Answer: False
◉ T/F: Electrons are localized in Valence Bond..
Answer: True
◉ T/F: When the hybrid orbitals combine, there is a large gap
between the bonding and anti bonding orbitals..
Answer: True
, ◉ Bonding in Tetrahedral C results in......
Answer: Sigma bonds.
◉ Bonding in Graphite.
Answer: 3 sp2 orbitals; trigonal planar; sigma bond
◉ Is graphite localized ?.
Answer: Has a localized sigma bond network but has a delocalized pi
network over the whole sheet of atoms.
◉ What does a larger electron cloud provide?.
Answer: Higher boiling point and more surface area to overcome
LDF's.
◉ Can you rotate around a double bond?.
Answer: No - bonds will break.
◉ What is a sigma bond?.
Answer: Single covalent bond (sp2-sp2 overlap).
◉ What is a Pi Bond?.
