intermolecular forces Flashcards
movement of solid
held by very strong forces because of attraction
particles are not free to move
particles vibrate about in fixed positions
density, diffusibility, compressibility, volume and shape, and thermal expansibility of solid
-very high
-extremely slow
-slightly compressible
-has fixed volume and shape
-expands slightly when heated
movement of liquid
held by strong forces of attraction
particles are able to slide past one another
density, diffusibility, compressibility, volume and shape, and thermal expansibility of liquid
-high
-slow
-slightly compressible
-assumes the shape of the container it occupies
-has fixed volume
-expands slightly when heated
because in the solid and liquid states particles are closer together, we refer to them as what?
condensed phases
total disorder, much empty space; particles have complete freedom of motion, particles are far apart
gas
disorder, particles or clusters of particles are free to move relative to each other, particles are close together
liquid
ordered arrangement, particles are essentially in fixed positions, particles are close together
crystalline solid
Attractive force between molecules, responsible for keeping matter in solid or liquid phase
intermolecular attraction
force which keeps molecules together
intramolecular attraction
bonding electrons shared equally between two atoms. no charges on atoms
nonpolar covalent bond
bonding electrons shared unequally between two atoms. partial charges on atoms
polar covalent bond
Result from the formation of temporary dipoles, as illustrated here for two nonpolar diatomic molecules
london dispersion forces
the tendency of an electron cloud to distort
polarizability
molecules that have permanent dipoles are attracted to each other. molecules are close to each other
dipole-dipole interactions
when H is bonded to NOF.
hydrogen bonding
important force in solutions of ions. the strength of these forces are what make it possible for ionic substances to dissolve in polar solvents
ion-dipole
results from the net inward force experienced by the molecules on the surface of a liquid
surface tension
resistance of a liquid to flow. it is related to the ease with which molecules can move past each other. increases with stronger intermolecular forces and decreases with higher temperature
viscosity
an attraction between unlike molecules.
adhesion
intermolecular attraction between like molecules
cohesion
broader term that includes evaporation and also boiling.
vaporization
gaseous state of a substance which is normally a liquid or solid at room temperature
vapor
substances that evaporate readily. examples are alcohol, gasoline, paint thinner, and dry cleaning solvents
volatile substances
at any temperature, some molecules in a liquid have enough energy to escape. as the temperature rises, some molecules that have enough energy to escape increases
vapor pressure
temperature at which its vapor pressure equals atmospheric pressure
boiling point
normal boiling point
760 torr
the more polar the molecule, the higher is its what
boiling point
