3.3: Unit 3 Practice Problems
Exercise 1
Determine all symmetry elements and all unique symmetry operations of the following molecules:
a)
b)
c)
d)
e) bromine tetrafluoride
f) Boric acid
g) Dinitrogen tetroxide
h)
i)
j)
k)
l)
m)
- Answer
-
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
k)
l)
m)
Exercise 2
When is a molecule chiral?
a) It has no mirror planes
b) It is has no inversion center
c) It has no principal axis
d) It has no rotation reflections (improper rotations)
- Answer
-
d) It has no rotation reflections (improper rotations)
Exercise 3
If a molecule has a principal axis C n , and n additional C 2 axes standing perpendicular to C n then it belongs to
a) A dihedral point group
b) A rotational point group
c) A low symmetry point group
d) A high symmetry point group
- Answer
-
a) A dihedral point group
Exercise 4
Which of the following molecules are chiral:
a) CH 4
b) CHCl 3
c) HCFClBr
d) HOF
e) BHFCl
- Answer
-
c) HCFClBr
Exercise 5
Determine the point groups of the molecules at symmetry.otterbein.edu/challenge/index.html until you feel that you can determine point groups effortlessly
Dr. Kai Landskron ( Lehigh University ). If you like this textbook, please consider to make a donation to support the author's research at Lehigh University: Click Here to Donate .