Chemistry - Chapter 11: Intermolecular Forces

intramolecular forces

ionic bonding and covalent bonding

intermolecular forces

LDFs, dipole-dipole forces, hydrogen bonding, and ion-dipole

intermolecular forces

strongly affected by physical changes

intramolecular forces

not strongly affected by physical changes

intramolecular forces

the stronger forces

intermolecular forces

the weaker forces

van der waals forces

dipole-dipole, hydrogen bonding, and LDFs

other attractive forces

ion-dipole and ion-ion

dipole-dipole

intermolecular forces that occur between polar molecules due to the positive end of one molecule attracting the negative end of another. only important when molecules are close to eachother

hydrogen bonding

dipole-dipole interactions experienced when H is bonded to NOF, and are even stronger.

london dispersion forces

attractions between an instantaneous dipole and an induced dipole. are temporary charges. present in all molecules, polar or nonpolar.

polarizability

the tendency of an electron cloud to distort in the LDF way

instantaneous dipole

when two atoms come into contact and their electrons repel, making one end temporarily positive and temporarily negative

induced dipole

an atom that has been affected by an instantaneous dipole attracts another atom, unaffected, and makes it have positive and negative parts.

vapor pressure

the pressure exerted by a vapor in equilibrium with its liquid phase. occurs when the rate of evaporation equals the rate of condensation, resulting in a constant number of gas molecules that exert pressure on the walls of the chamber.

increases

as temperature increases, vapor pressure…

due to the increase in kinetic energy allowing more molecules to transfer into the gas phase

why does vapor pressure increase as temperature increases?

strong

lower vapor pressures are associated with IMFs that are… (strong/weak)

volatile liquid

a liquid that evaporates easily

stronger

long, skinny molecules have.. (stronger/weaker) dispersion forces

due to increased surface area, because a large surface area makes the electron cloud more polarizable

why do skinny molecules have stronger dispersion forces?

stronger

the strength of dispersion forces tends to be (stronger/weaker) with more molecular weight

large atoms have larger electron clouds which are easier to polarize

why is the strength of dispersion forcers higher with higher molecular weight?

hydrogen bonding

all oxyacids (acid containing oxygen)