1. The number of different constitutional isomers that can be drawn for C2H4Br2 is equal to
a.1
b. 2
c.3
d. 4

2. The order of boiling points of the simple alkanes CH4, C2H6, and C3H8 is
a. CH4 < C2H6< C3H8
b. CH4 > C2H6> C3H8
c. C2H6 < CH4 < C3H8
d. CH4 < C2H6 > C3H8

3.Which of the following statements about pi molecular orbitals is/are correct?
a. pi molecular orbitals are cylindrically symmetric
b. most of the electron density in a pi molecular orbital is centered above and below the internuclear axis
c. when two atoms are connected by a double bond, both of these bonds are pi bonds
d. all of the above are correct