CHE

what is the difference between intramolecular and intermolecular forces

intra = attractive forces within a molecule that hold the molecule together : Inter= attractive forces between molecules, atoms or ions

define dispersion forces

fluctuations in the electron distribution which cause it to be temporarily asymetrical. creates a temporary dipole seperations and is present in every molecule/ substance . Magnitude depends on polarizability and shape.

define polarizability

the ease at which the electron distribution in the atom can be distorted . the larger the electron cloud is , the less the electrons are held by the nucleus the greater the polarizability . Polarizabilty also increases with mass.

How can the shape of a molecule affect the magnitude of dispersion forces

the shape determines how many interactions may occur between molecules . Dispersion forces increase with molar mass. Example a pill shaped molecule will have more surface area then a marble shaped molecule.

what can affect dispersion forces

molar mass, boiling point

how can boiling point affect dispersion forces

boiling point increases with increasing dispersion forces

define dipole-dipole forces

dipole moments occur in all polar molecules. draw the Lewis structure too see if its asymetrical .

how can polarity affect the strength of IMF with dipole-dipole molecules

boiling point and melting point increases with increasing polarity

define hydrogen bonding

special dipole moment force , when hydrogen is bonded to an F,O,N atom

list all the IMF forces in order

dispersion, dipole , hyrdrogen , ion-dipole

define ion-dipole forces

the positively charged end of a polar molecule such as H2O is attracted to negative ions and the negatively charged end of the molecule is attracted to positive ions.

where can each of the IMF be found

dispersion : all , dipole : polar molecules , hydrogen : H with FON ion dipole : ion and polar compound , ionic forces : two ions

surface tension IMF

the fewer the interactions the less stable , surface tension increases with IMF

viscosity and IMF

increases with molar mass and increasing intermolecular forces

rate of vaporization

increases with surface area , temperature and decereasing internolecular forces , higher temperature = higher vapor pressure

define volatile and nonvolatile

vaporize easily or harder

dynamic equilibrium

a state in a reversible reaction where the rate of the forward reaction equals the rate of the reverse reaction, so the amounts of reactants and products stay stable. rate of vaporization is constant while rate of condensation increases until equilibrium is reached .

define boiling point and normal boiling point

temperature at wich the liquids vapor pressure is equal to the external pressure . v.s temperature at which the vapor pressure of substance equals 1 ATM