review chem 127

Dec 6

Phase Changes

weak attraction, all molecules

stronger with polar molecules

hydrogen bonding is strongest version

Notice-- exam might link discussion of phase changes, equilibrium, DG )

melting (freezing) -- DH_fusion >0

DS_fusion >0

DG^o_fusion = +/- (- at T>mp)

vaporization -- DHvaporization >0

DS_evaporation >>0

DG^o _evaporation >0 at T>nBP

let's add solubility here

--DH to break down lattice but also

to solvate the solute

could be +/-

solubility can increase/decrease with temp.

DS > 0 generally

Keq - 1/ P(vapor)

can relate DG and VP at Temp other than BP

VP follows plot ln(P) vs. 1/T (K) is linear

Solutions--

units (molarity, molality)

where is each used?

Molarity-- all kinetics, equilibrium

Molality-- colligative properties

Raoult's law

FP depression, BP Elevation

Osmosis

Distillation