Chapter 12 and 13: Intermolecular Forces Flashcards
how are intemolecular forces to diffusion
IMF is inversely related to diffusion
what is the strength of gas’s IMF
weak
what is the strength of liquid’s IMF
moderate to strong IMF
what is the strength of solid’s IMF
strong IMF
as molecular motions increase, what happens to IMF
IMF decreases as molecular motions increase
how is kinetic energy related to IMF
IMF and KE are inversely related; when KE is high, IMF is low
what are intermolecular forces?
IMF is how atoms, molecules, and ions are attracted to or repelled from one another
intermolecular forces operate where in the molecule?
between molecules
IMF are based on what?
electrical interactions (unlike charges attract, like charges repel)
what does IMF do for molecules?
it hols them toghter in liquid and solids
strength of IMF depends on the BLANK of the molecules
structure
what are two key factors in the strength of IMF regarding structure of the molecule
the polarity and size of molecule
what is the boiling point of a liquid a measure of?
The strength of the IMF
the stronger the attractive forces in a liquid, the BLANK the temperature needed for separating the molecules form liquid state to a vapor
higher the temperature
what is indicated when size is similar but boiling point is different
the polarity of the molecules is different
what are the 4 types of IMF?
dipole-dipole forces, ion-dipole forces, hydrogen bonds, and dispersion forces
what is dipole-dipole force?
ineraction between 2 polar molecules
what is ion-diple force?
interaction between ion and a polar molecule
what is dispersion force?
interaction that occurs between ALL molecules
stength of dispersion force depends on what?
molecular size
what is hydrogen bond?
interaction between N-H, O-H, or F-H bond and a lone pair on an electronegative N, O, F atom on another molecule
polar molecules have what kind of charges?
opposite charges
the more polar a molecule the BLANK the dipole-dipole force
stronger
all hydrocarbons are nonpolar or polar?
nonpolar
what do disperions forces do to the electron cloud around a molecule or an atom?
dipsersion forces distort the cloud—think of a sphere being pulled into an egg shape
why are larger molecules more polarizable?
larger molecules have greater number of electrons, thus their electrons are farther from the nuclei
disperson forces generally increase with size, except when what bonds are involved?
hydrogen bonds
strength of ion-dipole forces depend on what 3 things?
charge of the ion, size of the ion, and polarity the molecule
in ion-dipole forces, what is the relationship between charge of ion and strength of force?
higher the charge, stronger the force
in ion-dipole forces, what is the relationship between size of ion and strength of force?
the smaller the ion, the stronger the ion-dipole force
in ion-dipole forces, what is the relationship between polarity of molecule and strength of force?
the more pole, the stronger the force
what is vapor pressure of a liquid
the pressure exerted by the apor particles in equilibrium with the liquid at constant temperature
in a closed container, rate of evaporation =
rate of condensation
how is vapor pressure of a liquid related to stregth of IMF
vapor pressure is inversely related to strength of IMF; stronger IMF equals lower vapor pressure
vapor pressure increases and what increases?
temperature
what is the strongest intermolecular force and why?
ion-ion force, they have the highest formal charge
what is the second strongest intermolecular force and why?
ion-dipole force, the charge of any ion is much greater than the charge of a dipole
why are hydrogen bonds stronger than most dipole dipole forces?
hydrogen bonds contain O, N, and F, which are 3 of the most electronegative elements, therefore the most polarized
describe partial polarity in London dispersion force
one side of an atom is slightly negative and one side is slightly positive… SLIGHTLY
in a liquid, the amount of heat energy stored equals what?
the precise amount of energy needed for the particles to be liberated to a gas
relationship between boiling point and attraction force
the stronger the attraction force of a substance, the higher the boiling point (or energy needed) to melt/boil/break the bonds
