•In
 general ionic forces the strongest, then hydrogen bonding,
 dipole-dipole and lastly dispersion for species of similar molar mass.
 •N2 (bpt -195oC)    O2 (bpt -183oC)
 •N2 (bpt -195oC)    CO (bpt -190oC)    H2O (bpt 100oC)
 •CH3F
 (-141.8oC)   CCl4 (-23oC)
 •NaCl
 (801oC mp)