pdpd is between polar molecules & polar molecules, which
means that you just have to determine if the 2 molecules are polar
or not.
idid is between non-polar & non-polar.
hydrogen bonding can ONLY OCCUR between a hydrogen atom attached to a highly
electronegative atom (N,O or F) and a lone pair of electrons on the highly
electronegative atom (N, O or F) of the other molecule.
as for gaseous state thing, is your question about ideal gas law
or something, specify?