Chapter 11: Fluids and Intermolecular Forces Flashcards
what do INTRA molecular attractions exist between?
chemical bonds (like the attraction between H+ and Cl- in HCl)
what do INTER molecular attractions exist between?
molecules (like the attraction between one HCl molecule and another HCl molecule)
which forces are weaker: INTRA molecular forces or INTER molecular forces?
Inter
what type of INTER molecular force involves instantaneous dipole moments?
London dispersion forces
what does the term ‘instantaneous dipole’ describe?
when a neutral atom is temporally develops a slight dipole such that it becomes attracted to another neutral atom that has temporally developed a slight dipole
what does the term ‘polarizability’ describe?
the ease with which a neutral atom can temporarily develop a slight dipole (for use in dispersion force attraction)
does polarizability increase or decrease as the number of an atom’s/molecule’s electrons increases?
polarizability INCREASES as the atom’s/molecule’s number of electrons increases
dispersion force strength increase or decrease as the atomic/molecular size increases?
increases
which molecular shape has stronger dispersion forces: long/cylindrical shapes or short/spherical shapes?
long cylindrical shapes
does dipole:dipole force get stronger or weaker as polarity increases?
stronger; dipole:dipole force follows from permanent (if weak) dipole
why does molecular size/shape impact the strength of dispersion forces?
bc dispersion forces get stronger with increased surface area
if two molecules are about the same size/shape, how do you determine which one has the stronger intermolecular forces?
The more polar molecule will have the stronger intermolecular forces
(dipole:dipole force is the tie breaker here)
if two polar molecules are different sizes, how do you determine which one has the stronger intermolecular forces?
the bigger molecule will have the stronger intermolecular forces
(even if both molecules have dipole or dipole:dipole forces, when they’re two different sizes, you compare them by their dispersion forces)
does COhesion cause molecules to stick to themselves or to surfaces?
themselves
does ADhesion cause molecules to stick to themselves or to surfaces?
surfaces
