Chapter 13 Notes #3 Intermolecular Forces Chemistry Chapter 13 Notes #3 Intermolecular Forces

Intermolecular Forces Intramolecular forces – within Ionic, covalent, and metallic bond Intermolecular Means “between” or “among” Forces of attraction between molecules 3 Types Dispersion Dipole-Dipole Hydrogen Bonds

Dispersion Forces Occurs with (mainly) non-polar molecules Weak forces Based on temporary dipoles Dipoles = areas of positive and negative due to unequal dispersion of electrons Temp. dipoles get created when atoms or particles collide, shifting the density of the particle

Dispersion Forces Temporary dipole Temporary dipole Temporary dipoles are attracted

Dipole-Dipole Forces Occurs between (mainly) polar molecules Much stronger than dispersion forces Permanent Dipoles Areas of positive and negative due to unequal sharing of electrons in a polar covalent bond Attraction between positive and negative

Dipole-Dipole Forces

Hydrogen Bonds Occurs between H in one molecule and F, N, or O in another molecule Each has at least one lone e- pair where the bonding can occur Special type of dipole -dipole force Strongest intermolecular force Strong because of the high difference in electronegativity and mass between the atoms

Hydrogen Bonds