PPT Slide
- Dispersion forces are weak forces caused by momentary oscillations of electron density causing a momentary dipole in a neighboring molecule.
- When particles collide, electron clouds are repelled, and electron density is momentarily greater in one region of the particle than in another.
- Transitory dipoles are induced in both particles, which, in turn, induce instantaneous dipoles in adjacent particles.
- Dispersion forces generally increase with molar mass.
- Greater contact allows the dispersion forces to act at more points, so n-pentane has a higher boiling point than neopentane (same molar mass).
Notes: