posted by Casey .
Which pair of molecules has the strongest dipole-dipole interactions?
a- CO2 and CO2
b- CO2 and CH4
c- NH3 and NH3
d- NH3 and CH4
e- CH4 and CH4
how do you figure out the answer to this question?
1. You know what makes a dipole.
2. You review to see which has two dipoles.
Symmetry is a big clue in this. CO2 are linear molecules, CH4 is a symmetrical (tetrahedral) molecule, and NH3 is not symmetrical, with a double unshared pair of electrons on one side.