CHEM-C 243 Lecture Notes - Lecture 10: Trigonal Planar Molecular Geometry, Chemical Polarity, Triple Point
Document Summary
Section 1- intermolecular forces: intramolecular attraction- within a molecule (bonds, intermolecular attraction/forces- between molecules. Must be able to determine stronger and weaker in different molecules. Apply to all states of matter, though ideally not gases. Every im attraction weaker than weakest covalent bond: types of intermolecular forces (strongest to weakest) Ion ion attractions- not counted as intermolecular; half intra, half inter equal-strength attraction between ions; ie. in solid salt crystal, every na + is attracted to every cl- (all are bonds) Hydrogen bonding (strongest)- special dipole dipole interaction between h atom in a polar n-h, o-h, or f-h bond and an electronegative o, n, or f atom; not a bond. Between 1 molecule w/ h and a highly electronegative element (n, o, f) Steric hindrance- prevents hydrogen bonding; if there is a bunch of stuff around an electronegative element, an h may not be able to get to it.
