chem topic 5 Flashcards
what is intermolecular forces
attractive forces between molecules
what is the state of a substance
balance between IMF (hold particles together) and kinetic energy (moves particles apart)
what is boiling point
-liquid to gas phase transition
-requires the IMF to break
-high boiling point=strong IMF
4 types of IMF
london dispersion
dipole-dipole
hydrogen bonding
ion dipole
are IMF weaker than covalent bonds?
yes (smaller charges over long distance)
london dispersion
-present in all molecules
-distribution of electrons is symmetric
-attraction between dipole and induce dipole
two factors that affect the strength of london dispersion forces
polarizability (ability to move around, increases down table)
molecular shape
molecules with greater surface area in LDF will have
stronger forces
dipole dipole force
-molecules with dipole are attracted to each other
-pos attracted to neg end
increase boiling point
-larger dipole, stronger DDF
hydrogen bonds
-when H is bonded to N,O,F the dipole is unusually strong
are hydro bonds stronger than DDf?
yes
whats a doner and acceptor?
-hydro bonding
-H doner
-N,O,F acceptor
ion dipole forces
-ion and polar molecule
-strength of interactiono
order of IMF strength from large to small
ion dipole-hbond-DDF-LDF
what happens if one molecule is much larger than the other? what happens if similar
L: LDF will dominate
S: strongest IMF will dominate
