Are instantaneous dipole-induced dipole forces stronger than permanent dipole forces??

Question

If so, why are they stronger. 

 

Also do you identify a compound with permanent dipoles if it is a polar molecule or if there are polar bonds??

Answer 1

Instantaneous dipole-induced dipole forces (dispersion) are not stronger than permanent dipole, and as suggested by the name, they do not last very long and are fleeting attractive forces.   You identify a permanent dipole by determining it the molecule is polar.  Just because it has polar bonds does not make it a permanent dipole, because it depends on the geometry of the molecule.  And example might be in carbon tetrachloride, CCl₄. You have 4 polar bonds, but the molecule is not polar, and thus not a dipole because all polarity is canceled.