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Terms in this set (47)

listed weakest to strongest

(1,2,3 are all Van der Waals Forces; every molecule has these)

1) london dispersion forces
-nonpolar compound in a nonpolar environment
-exists in any pure chemical sample; increases the energy of attraction in all matter
-only force in nonpolat substance (N2, O2, CO2, CH4, Ar, He, Ne); contribute to interactions in polar substances (small)
-arises when an instantaneous dipole in one particle induces a dipole in another particle. Electrons in this position affect electrons in another particle (kind of like waves propagating); not permanent or very strong
-a temporary distortion of the electron cloud in an atom or molecule
-stronger for more polarizable particles
-one particle can interact/induce multiple other molecules or atoms

2) dipole-dipole forces
-polar compound in a polar environment; ex, water
-only in polar molecules; need a permanent dipole
-electrostatic attractions between oppositely charged ends of polar molecules
-strength of interactions increases with molar mass
-the positive pole of one polar molecule attracts the negative pole of another

3) hydrogen bonds
-very strong special subset of dipole-dipole
-very large separation of charges
-only in molecules with H bonded to O, N, F
-boiling points increase; abnormally high; based on molar mass trend

4) ionic bonds (ion-dipole)
-ionic compound in a polar environment
-electrostatic force between ions; complete separation of charges
-present in all ionic compounds (metal and nonmetal)
-extremely high boiling points