Question

which probably has the lowest boiling point at 1.0 atm pressure.

A) C6H14
B) C3H8
C) C4H10
D) C5H12
E) C2H6

Answer 1

i was told that the molecule with the lowest weight has the lowest boiling point because it is the least polar as well.

Answer 2

Partly yes and partly no. The molecule likely to have the lowest boiling point will be the one with the lowest molar mass. The polarity plays a VERY important role but it is another factor to consider; i.e., just because a molecule has a low molar mass doesn't mean it is the least polar.

Answer 3

c2h6