Chem Ch11.txt

ln P2/P1 = ΔHvap/R (1/T2 –1/T1)

ln Pvap = ΔHvap/R (1/T) + ln β

• y = ln Pvap
• m = ΔHvap/R
• x = (1/T)
• b = ln β

q = n ΔH

q = m Cs ΔT

How easily a molecule's electron cloud can be distorted. More polarizable = easier to distort = higher dispersion forces.

A permanent separation of charges in a molecule - the molecule has a permanent dipole moment, and will display dipole-dipole forces.

When the rate of evaporation = the rate of condensation in a closed system at a stable temperature.

Pressure of a gas that is in dynamic equilibrium with its liquid.

Intermolecular forces that are the result of fluctuations in the electron cloud of an atom or molecule.

Intermolecular forces found in polar molecules.

Intermolecular forces found in polar molecules that contain hydrogen atoms directly bonded to N, O, or F.

Intermolecular force found when an ionic compound is mixed with a polar compound, esp. in aqueous solutions.

• London dispersion
• dipole-dipole bonding
• hydrogen bonding
• ion-dipole bonding

Surface tension decreased with decreasing intermolecular forces.

Viscosity is greater in substances with stronger intermolecular forces. Viscosity also depends on molecule shape and temperature, increasing in longer molecules and in lower temps.

Adhesive (attraction between molecules in a liquid and the sides of the tube) and cohesive (attraction between molecules in a liquid) forces.

Weak forces result in a high vapor pressure.

The temperature at which vapor pressure = external pressure. "Normal" boiling point is at 1 atm.

• gas --> solid: deposition
• solid --> gas: sublimation

Fusion.

The point in a phase diagram where all three phases of a substance are equally stable and can exist in equilibrium.

The point in a phase diagram that represents the temperature and pressure above which a supercritical fluid exists.