PURDUE CHEM 115 FINAL EXAM 2026
COMPLETE PRACTICE QUESTIONS,
VERIFIED CORRECT ANSWERS AND
COMPREHENSIVE GENERAL
CHEMISTRY STUDY GUIDE
Ether - CORRECT ANSWER -
Kelvin - CORRECT ANSWER -=273.15+ Degree C
Valence Bond Theory - CORRECT ANSWER -A model that attempts to
reconcile the shapes of molecules with those of atomic orbitals through the
concepts of orbital overlap and hybridization (429).
hybridization - CORRECT ANSWER -a postulated process of orbital mixing
to form hybrid orbitals (430).
hybrid orbitals - CORRECT ANSWER -an atomic orbital postulated to form
during binding by the mathematical mixing of specific combinations of
nonequivalent orbitals on a given atom (430).
sp hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing of
one s and one p orbital of a central atom (430).
,sp2 hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing of
one s and two p orbitals of a central atom (432).
sp3 hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing of
one s and three p orbitals of a central atom (432).
sp3d hybrid orbitals - CORRECT ANSWER -an orbital formed by the mixing
of one s, three p, and one d orbital of a central atom (433).
sp3d2 hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing
of one s, three p, and two d orbitals of a central atom (434).
How to determine hybrid orbitals from molecular formula - CORRECT
ANSWER -1. take molecular formula, 2. create lewis structure, 3. determine
molecular shape and electron group arrangement, 4. determine hybrid
orbitals (434) - two helpful charts at bottom of page.
sigma bond - CORRECT ANSWER -a type of covalent bond that arises
through end-to-end orbital overlap and has most of its electron density
along an imaginary line joining the nuclei (437).
pi bond - CORRECT ANSWER -a covalent bond formed by sideways overlap
of two atomic orbitals that has two regions of electron density, one above
and one below the internuclear axis (437).
What are the major principles of the Valence Bond theory? - CORRECT
ANSWER -1. a covalent bond forms when orbitals of two atoms overlap and
, a pair of electrons occupy that overlap region. 2. there are opposing spins of
the electron pair. 3. there is a max. overlap of bonding orbitals (greater
overlap = closer nuclei to electrons/stronger bond)
What are features of hybrid orbitals? - CORRECT ANSWER -1. the number of
orbitals equals the number of atomic orbitals mixed, 2. the type of orbitals
varies, 3. the shape and orientation of a hybrid orbital maximizes its
overlap with the orbital of the other atom in the bond.
Why is rotation about the bond axis restricted in molecules containing a pi
bond? (i.e. either a double/triple bond) - CORRECT ANSWER -a pi bond
restricts rotation because the p orbitals must be parallel to each other to
overlap most effectively.
What are the main differences between molecular mechanics, semi-
empirical and Ab Initio computational models? - CORRECT ANSWER -1.
Molecular mechanics is used when a molecule is too big to effectively use
the semi-empirical method. 2. Semi-empirical calculations can be done
much faster than Ab Initio calculations, but results can be erratic. 3. Ab
Initio gives very good qualitative results and they grow more accurate as
size of molecule decreases.
What are the major benefits/goals of computational chemistry? - CORRECT
ANSWER -1. Computational chemistry tools can be used to investigate a
much wider variety of chemical species than are normally accessible to the
experimental chemist. 2. is also allows chemists to think more clearly about
issues that are really central to chemistry - structure, stability, and
reactivity - than would be possible without the use of a computer. 3. goals
are to eliminate/reduce time consuming experiments, provide insight into
existing experimental data, or guide new experimental studies.
COMPLETE PRACTICE QUESTIONS,
VERIFIED CORRECT ANSWERS AND
COMPREHENSIVE GENERAL
CHEMISTRY STUDY GUIDE
Ether - CORRECT ANSWER -
Kelvin - CORRECT ANSWER -=273.15+ Degree C
Valence Bond Theory - CORRECT ANSWER -A model that attempts to
reconcile the shapes of molecules with those of atomic orbitals through the
concepts of orbital overlap and hybridization (429).
hybridization - CORRECT ANSWER -a postulated process of orbital mixing
to form hybrid orbitals (430).
hybrid orbitals - CORRECT ANSWER -an atomic orbital postulated to form
during binding by the mathematical mixing of specific combinations of
nonequivalent orbitals on a given atom (430).
sp hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing of
one s and one p orbital of a central atom (430).
,sp2 hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing of
one s and two p orbitals of a central atom (432).
sp3 hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing of
one s and three p orbitals of a central atom (432).
sp3d hybrid orbitals - CORRECT ANSWER -an orbital formed by the mixing
of one s, three p, and one d orbital of a central atom (433).
sp3d2 hybrid orbital - CORRECT ANSWER -an orbital formed by the mixing
of one s, three p, and two d orbitals of a central atom (434).
How to determine hybrid orbitals from molecular formula - CORRECT
ANSWER -1. take molecular formula, 2. create lewis structure, 3. determine
molecular shape and electron group arrangement, 4. determine hybrid
orbitals (434) - two helpful charts at bottom of page.
sigma bond - CORRECT ANSWER -a type of covalent bond that arises
through end-to-end orbital overlap and has most of its electron density
along an imaginary line joining the nuclei (437).
pi bond - CORRECT ANSWER -a covalent bond formed by sideways overlap
of two atomic orbitals that has two regions of electron density, one above
and one below the internuclear axis (437).
What are the major principles of the Valence Bond theory? - CORRECT
ANSWER -1. a covalent bond forms when orbitals of two atoms overlap and
, a pair of electrons occupy that overlap region. 2. there are opposing spins of
the electron pair. 3. there is a max. overlap of bonding orbitals (greater
overlap = closer nuclei to electrons/stronger bond)
What are features of hybrid orbitals? - CORRECT ANSWER -1. the number of
orbitals equals the number of atomic orbitals mixed, 2. the type of orbitals
varies, 3. the shape and orientation of a hybrid orbital maximizes its
overlap with the orbital of the other atom in the bond.
Why is rotation about the bond axis restricted in molecules containing a pi
bond? (i.e. either a double/triple bond) - CORRECT ANSWER -a pi bond
restricts rotation because the p orbitals must be parallel to each other to
overlap most effectively.
What are the main differences between molecular mechanics, semi-
empirical and Ab Initio computational models? - CORRECT ANSWER -1.
Molecular mechanics is used when a molecule is too big to effectively use
the semi-empirical method. 2. Semi-empirical calculations can be done
much faster than Ab Initio calculations, but results can be erratic. 3. Ab
Initio gives very good qualitative results and they grow more accurate as
size of molecule decreases.
What are the major benefits/goals of computational chemistry? - CORRECT
ANSWER -1. Computational chemistry tools can be used to investigate a
much wider variety of chemical species than are normally accessible to the
experimental chemist. 2. is also allows chemists to think more clearly about
issues that are really central to chemistry - structure, stability, and
reactivity - than would be possible without the use of a computer. 3. goals
are to eliminate/reduce time consuming experiments, provide insight into
existing experimental data, or guide new experimental studies.
