Chapter 12 Flashcards
phase
A physically distinct and homogeneous part of a system
intermolecular forces
The attractive and repulsive forces among the particles- molecules, atoms, or ions- in a sample of matter.
phase change
A physical change from one phase to another, usually referring to a change in physical state
condensation
The process of a gas changing into a liquid
vaporization
The process of changing from a liquid to a gas
freezing
The process of cooling a liquid until it solidifies
melting(fusion)
The change of a substance from a solid to a liquid
sublimation
The process by which a solid changes directly into a gas
deposition
The process of changing directly from gas to solid
heat of vaporization
The enthalpy change occurring when 1 mol of a liquid substance vaporizes.
heat of fusion
The enthalpy change occurring when 1mol of a solid substance melts
heat of sublimation
The enthalpy changes occurring when of a solid substance changes directly to a gas.
heating-cooling curve
A plot of temperature vs. time for a substance when heat is absorbed or released by the system at a constant rate
dynamic equilibrium
The condition at which the forward and reverse relations are taking place at the same rate, so there is no net change in the amounts of reactants or products
vapor pressure
The pressure exerted by a vapor at equilibrium with its liquid in a closed system
Clausius-Clapeyron equation
An equation that expresses the linear relationship between vapor pressure P of a liquid and temperature T.
boiling point
The temperature at which the vapor pressure of a gas equals the external pressure
melting point
The temperature at which the solid and liquid forms of a substance are at equilibrium
phase diagram
A diagram used to describe that stale phases and phase changes of a substance as a function of temperature and pressure
triple point
The pressure and temperature at which three phases of a substance are in equilibrium. In a phase diagram, the point at which three phase-transition curves meet.
critical point
The point on a phases diagram above which the vapor cannot be condensed to a liquid; the end of the liquid-gas curve
van der Waals radius
One-half of the shortest distance between the nuclei of identical non bonded atoms
ion-dipole force
The intermolecular attractive force between an ion and a polar molecule.
dipole-dipole force
The intermolecular attraction between oppositely charged poles of nearby polar molecules
hydrogen bond
A type of dipole-dipole force that arises between molecules that have an H atom bonded to a small, highly electronegative atom with lone pairs, usually N,O, or F.
polarizability
The ease with which a particle’s electron cloud can be distorted
dispersion force
The intermolecular attraction between all particles as a result of instantaneous polarizations of their electron clouds; the intermolecular force primarily responsible fro the condensed states of non polar substances
