chap 6 Flashcards
(11 cards)
order of intermolecular forces strongest to weakest
Ion-dipole
hydrogen bonding
dipole-dipole
dipole-induced dipole
london dispersion
characteristics of intermolecular forces
weaker than intra, act over long distances influence physical properties of substances(BP, FP,surface tension, vapor pressure etc)
define london dispersion forces. strength depends on?
all molecules can interact via instantaneous dipoles. due to distortions in e- cloud. creates instantaneous dipole moment which can induce same in neighbors. strength depends on size and shape. larger area= higher BP
define polarizability in context to london dispersion
with larger atoms or molecules you get larger e- clouds and with more distortion of e- cloud you get stronger dipoles.
what is dipole-induced dipole?
dipole=polar induced dipole=normally nonpolar
H2O has permanent dipole and it will connect to O2 inducing a dipole in it. ALLOWS FOR NONPOLAR SOLUTES TO DISSOLVE IN POLAR SOLVENTS(water).
what is dipole-dipole interactions?
both are polar
polar molecules are attracted to each other via this.
what is hydrogen bonding?
occur when hydrogen is bonded to O, N or F. H2O can donate 2 hydro and accept 2 hydro.
what are dipole- ion interactions?
cations and anions can interact with molecules that have a permanent dipole. Na+ can have approx 6 perm dip around it. same with Cl- but arrow pointed away.
define sphere of hydration in regards to dipole-ion interaction
when dissolved in water ions are surrounded by a number of H2O molevules that are organized in multiple layers.
influence of intermol forces on viscosity
more connections a molecule has means more viscous. or higher molar mass higher viscosity. or more intermol more viscosity
influences of intermol forces on BP
the more intermol forces the higher the BP
