IMF unit Flashcards
simple cubic structure
atoms per unit cell: 1
coordination number: 6
edge length: 2r
packing efficiency: 52%
body- centered
atoms per unit cell: 2
coordination number: 8
edge length: 4r/square root 3
packing efficiency: 68
face centered
atoms per unit cell: 4
coordination number: 12
edge length: (2 square root 2)r
packing efficiency: 74%
h-bonding
type of super dipole dipole
h bonded to very electronegative (N,F,O)
large imf ve large KE
large imf= molecues close together, is a solid or liquid
high imf= higher tension
large KE= molecules moving and seperate becoming gas
ion-dipole force
strongst.
between ion and pernament dipole (+ and -)
charged ion attracted to opposite charged nd of the dipole
dispersion force
weakest
unequal e- distribution
creates temporary dipole
as e- increase (and size of particle goes up), it increases
one side more negative, other side more positive
ion induced
involves an ion and non polar (o charge)
dipole induced
involves an ion and dipole (+ and -)
dipole-dipole
2 polar molecules
attracted to positive of one and the negative of other
liquids imf
capillary action
the ability of the liquid to flow against gravity up a narrow tube
cohesive forces: attraction between liquid molecules
adhesive forces: attraction between liquid molecules and surface of a tube
liquid IMF
viscosity
flow of liquid
stronger imf increase viscosity
longer chain and more e- higher viscosity
types of solids:
molecular solids, network
molecular: combinations of IMF
network: high melting point, covalent bonds, diamond with 3-dimensional shape.examples: gemstones
types of solids
metallic, ionic
metallic: high delocalized bonds. allow easy movement of electrons within the atom
ionic: Made up of positive and negative ions and held together by electrostatic attractions.
types of liquid
volatile: weak imf, easily vapourize
nonvolatile: strong imf
ex: h2o
