Educator

Vapor Pressure, Boiling Point, Phase Diagrams

• Vapor pressure of liquid: example of equilibrium, equal and opposite rates of evaporation and condensation

• B.p. temp. at which v.p. = external P.

• Normal b.p. temp. at which v.p. = exactly 1 atm. or 760 torr.

• Reduce pressure, reduce b.p. Vacuum distillation

• Intermolecular forces and surface tension; viscosity

• Enthalpy of vaporization > enthalpy of melting due to total breaking of intermolecular forces

• Learn how to draw a general phase diagram

• Significance of: triple point; critical point; difference between dense gas and liquid is absence of surface

• Supercritical carbon dioxide – useful solvent