Chem 162 Exam Questions with 100%
Correct Answers
Axial lone pairs - ANSWER-Lies on axis of molecule where is srongly repels the
electron pairs in the three equatorial bones
Equatorial lone pair - ANSWER-Lies on molecule's equator, where is strongly repels
electron pairs in the two axial bonds
sigma bond - ANSWER-all single covalent bonds. A bond formed when two atomic
orbitals combine to form a molecular orbital that is cylindrically symmetrical around the
axis connecting the two atomic nuclei
Head on overlap of hybridized orbitals or atomic orbital of hydrogen
pi bond - ANSWER-Orbitals are perpendicular to the inter nuclear axis.
a bond that is formed when parallel orbitals overlap to share electrons.
Side by side overlap. Prevents free rotation about that axis. Parallel overlap of p
orbitals.
Sigma or pi: single bond - ANSWER-Sigma
Sigma or pi: double bond - ANSWER-One sigma + one pi
Sigma or pi: triple bond - ANSWER-One sigma + two pi
hybrid orbitals - ANSWER-orbitals of equal energy produced by the combination of two
or more orbitals on the same atom. Amplitudes concentrated on one side of the
nucleus, allowing hybrid orbitals to overlap more effectively than other orbitals and form
stronger bonds
What does this notation mean: (C2sp^3,H1s) - ANSWER-A sigma bond formed by spin-
pairing a carbon electron in a hybridized sp^3 orbital (from 2s and 2p orbitals) and a
hydrogen electron in the 1s orbital
Diamagnetic substance - ANSWER-Moves out of magnetic field. All electrons in
molecule are paired.
Paramagnetic substance - ANSWER-Moved into magnetic field. Molecule has unpaired
electrons
, When can halogens in period 3 (Cl, Br, I, etc.) and below form more than one bond? -
ANSWER-In compounds with more electronegative atoms
Wavelengths of UV light - ANSWER-Red: 665 nm -> Violet: 400 nm
T shaped - ANSWER-Ax3e2
Square pyramidal - ANSWER-Ax5e
Trigonometry bipyramidal - ANSWER-Ax5
Lewis structure: Prediction for number of bonds - ANSWER-((octet rule)(number of
atoms)-(number of electrons))/2
Formal Charge - ANSWER-wants - has
C wants 4 and has ___ through this many bonds
bond order - ANSWER-(# of bonding electrons - # of antibonding electrons) / 2
How strong is this bond? - ANSWER-Bond order
Seesaw - ANSWER-AX4E
Least volatile - ANSWER-Highest boilig point. Strongest intermol.
H bond - ANSWER-F o n. Must bond t h in mol and have nonbonding e (lone pair)
Electron affinity - ANSWER-Change in energy when adding an electron to a neutral
Atom. First order can be negative and second order can be positive. That would mean
first order is favorable
Number of x and e (steric number) in axe determines - ANSWER-Hybridization
Sigma or pi bonds? - ANSWER-Sigma = hybridized
Pi = unhybridized orbitals
Dipole moment equation - ANSWER-Charge•distance
Sp mixing in - ANSWER-B c n
Length or strength of bond?? - ANSWER-Bond order
Predict number of bonds in NO+ - ANSWER-Can use bond order to tell you number of
bonds
Degenerate - ANSWER-Equal in energy (MO)
Correct Answers
Axial lone pairs - ANSWER-Lies on axis of molecule where is srongly repels the
electron pairs in the three equatorial bones
Equatorial lone pair - ANSWER-Lies on molecule's equator, where is strongly repels
electron pairs in the two axial bonds
sigma bond - ANSWER-all single covalent bonds. A bond formed when two atomic
orbitals combine to form a molecular orbital that is cylindrically symmetrical around the
axis connecting the two atomic nuclei
Head on overlap of hybridized orbitals or atomic orbital of hydrogen
pi bond - ANSWER-Orbitals are perpendicular to the inter nuclear axis.
a bond that is formed when parallel orbitals overlap to share electrons.
Side by side overlap. Prevents free rotation about that axis. Parallel overlap of p
orbitals.
Sigma or pi: single bond - ANSWER-Sigma
Sigma or pi: double bond - ANSWER-One sigma + one pi
Sigma or pi: triple bond - ANSWER-One sigma + two pi
hybrid orbitals - ANSWER-orbitals of equal energy produced by the combination of two
or more orbitals on the same atom. Amplitudes concentrated on one side of the
nucleus, allowing hybrid orbitals to overlap more effectively than other orbitals and form
stronger bonds
What does this notation mean: (C2sp^3,H1s) - ANSWER-A sigma bond formed by spin-
pairing a carbon electron in a hybridized sp^3 orbital (from 2s and 2p orbitals) and a
hydrogen electron in the 1s orbital
Diamagnetic substance - ANSWER-Moves out of magnetic field. All electrons in
molecule are paired.
Paramagnetic substance - ANSWER-Moved into magnetic field. Molecule has unpaired
electrons
, When can halogens in period 3 (Cl, Br, I, etc.) and below form more than one bond? -
ANSWER-In compounds with more electronegative atoms
Wavelengths of UV light - ANSWER-Red: 665 nm -> Violet: 400 nm
T shaped - ANSWER-Ax3e2
Square pyramidal - ANSWER-Ax5e
Trigonometry bipyramidal - ANSWER-Ax5
Lewis structure: Prediction for number of bonds - ANSWER-((octet rule)(number of
atoms)-(number of electrons))/2
Formal Charge - ANSWER-wants - has
C wants 4 and has ___ through this many bonds
bond order - ANSWER-(# of bonding electrons - # of antibonding electrons) / 2
How strong is this bond? - ANSWER-Bond order
Seesaw - ANSWER-AX4E
Least volatile - ANSWER-Highest boilig point. Strongest intermol.
H bond - ANSWER-F o n. Must bond t h in mol and have nonbonding e (lone pair)
Electron affinity - ANSWER-Change in energy when adding an electron to a neutral
Atom. First order can be negative and second order can be positive. That would mean
first order is favorable
Number of x and e (steric number) in axe determines - ANSWER-Hybridization
Sigma or pi bonds? - ANSWER-Sigma = hybridized
Pi = unhybridized orbitals
Dipole moment equation - ANSWER-Charge•distance
Sp mixing in - ANSWER-B c n
Length or strength of bond?? - ANSWER-Bond order
Predict number of bonds in NO+ - ANSWER-Can use bond order to tell you number of
bonds
Degenerate - ANSWER-Equal in energy (MO)
