1) Which molecule is likely to be the most polar? This list
of electronegativities may be helpful:
H 2.1
Br 2.8
F 4.0
2) Which set of bond angles are the correct ideal values
for the molecule below. The subscripts are atom labels, not
the number of atoms in the molecule.
H1a—N—C1
H2a—C1—C2
C1—C2—O
C1—C2—H3
A 90° 90° 90° 180°
B 107° 109.5° 120° 120°
C 120° 90° 120° 180°
D 107° 109.5° 90° 120°
3) Given the Lewis structure of
SBr2 below, what is the approximate bond angle in
the molecule?
4) Which molecule is correctly matched with its
electron-pair geometry and molecular structure?
Electron-pair geometry Molecular structure
PCl3 trigonal planar trigonal pyramidal
SCl4 trigonal bipyramidal tetrahedral
NO2 trigonal planar bent
H2O trigonal planar linear
5) Given the electronegativities below, arrange these
linear molecules in order of increasing polarity. The central atom
is underlined.
H 2.1
P 2.1
C 2.5
S 2.5
O 3.5
Least polar to most polar:
P2O, COS, HPC, CS2
6) Which statement is true?
a) Non-polar molecules have an overall (net) dipole of zero but
may contain polar bonds.
b) Non-polar molecules have an overall (net) dipole but may
contain polar bonds.
c) Polar molecules have an overall (net) dipole and contain all
non-polar bonds.
d) Polar molecules have an overall (net) dipole of zero and
contain all non-polar bonds.
7) Which structure would result in a non-polar molecule if
all the peripheral atoms were the same?
8) Draw Lewis structures (the central atom is
underlined) in order to rank the molecules in order of
decreasing bond angle.
Largest to Smallest:
ClO3-, ClF2+, ClO3+
9) Given the Lewis structure of BF3 below,
what are the bond angles in the molecule?
a) All 90 degrees
b) All 120 degrees
c) 90 and 120 degrees
d) 120 and 180 degrees