Vapor Pressure
Equilibrium: rate of evaporation = rate of condensation
P at equilibrium = vapor pressure
When Pvap = Patm, T = boiling point
When Pvap = 1 atm, T = normal boiling point
In Phoenix, boiling point of H2O = 99oC
At sea level, b.p. of H2O = 100oC
At 9000 ft elevation, b.p. of H2O = 91oC (needs a pressure cooker to speed up cooking)