types intermolecular forces
Terms
undefined, object
copy deck
- london dispersion force or induced-dipole-induced dipole interaxn
-
-resultant transient dipole moment can induce dipole in an adjacent molecule
-weak electrostatic forces
-resp for liquefaction of nonpolar gases -
dipole-induced dipole interaxn or
debye induction force -
transient dipole induced by a permanent dipole
strongest interaxn -
keesom orientation forces
or
permanent dipole interaxn -
+ debye + london forces = Van der Waals forces
- resp for more substantive structure & molecular oredering found in liq - hydrogen bonds
-
small
large electrostatic field
approach high electronegative atoms -> interact electrostatically => form H bond - electronegative atoms
-
Fl
O
N
CL
S -
ion dipole interaxn
or
dipole induction by anion - affect molecular aggregation or ordering in a system
- state of ideal gas
- PV = nRT
- molar gas constant
- 0.0825L atm/mole deg
- anesthetic gases
-
nitrous oxide
halothane - compressed gases
-
oxygen
nitrous oxide
nitrogen
carbon dioxide - liquefable gases
- halohydrocarbons
- hydrocarbons
- used as propellants in aerosol prdts
- ethylene oxide
- gas used to sterilize or disinfect heat labile objects
- increase temp
- increast heat content or enthalpy
- melting
- solid -> liq
- vaporization
- liq-gas
- volatile liq
-
halothane
ether
methoxyflurane
used as inhalation anes - amyl nitrite
- volatile liq inhaled ofr its vasodilating eff in acute angina
- sublimation
- solid -> gas without liq
- ex of sublimation
-
camphor
iodide - freeze drying or lyophilization
-
form of vacuum drying
water removed by sublimation fr frozen prdt
useful for drying aquous solns or dispersion of heat or oxygen sensitive drugs or biologicals (protein, peptide) - deposition
-
reverse process -> vapor to liq
ex: sulfur
colloidal silicon dioxide - at room temp
- intermolecular in gases are nonexistent
- surface free energy
- work required to inc the surface area A of the liq by 1 area unit (milliNewtons)
- interfacial tension
-
free energy
work req to expant the interfacial area - rate of shear
- deformation of liq w/ time
- coefficient of viscosity
- indicates resistance to flow of adjacent layers of fluid
- fluidity
- reciprocal of viscosity
- dynes
- units of viscosity in CGS sys
- newtonian
- liquids consist of simple molecules and dilute dispersions
- non newtonian
-
-do not obey newtons equation of flow
-exhibit shear dependent or time dependent viscosity - ex of non newtonian
- heterogenous liq and solids
- shear thickening or dilatancy
-
inc in apparent viscosity
shear dependent viscosity - ex of shear thickening
- susp that have inc solids content of small deflocculated particles
- shear thinning or pseudoplasticity
-
dec in apparent viscosity
inc rate shear - ex of shear thinning
-
polymer
macromolecule soln - plastic or bingham body
- flocculated particles in conc susp that show no apparent response to low level stress
- flow
- begins only after a lmting yield stress/ valve is exceeded
- thixotropic
-
-display shear thinning behavior
- do not immediately recover their higher apparent
viscosity
when the rate of shear is lowered
-structural recovery is relatively slow compared w/ structural breakdown - thixotrophy
- occurs w/ heterogenous sys that involve a 3 dimentsional structure or network
- thixotrophy under shear
- structure breaks down and fluidity inc (gel-sol transformation)
- crystalline solids
-
fixed molecular order
distinct melting pt
anisotropicity - anisotropicity
- properties are not the same as all directions escept cubic crystals
- amorphous solids
- randomly arranges molecules nondistinct melting pt's
- isotropicity
- prop are the same all directions
- polymorphism
- condition wherein subs can exist in more than 1 crystalline form
- polymorphs
-
diff molecular arrangements
diff crystal lattice structure - ex of drug class of polymorphic behavior
-
steroids
faaty (triglyceride)excipients - fatty (triglyceride) excipients
-
theobroma oil
cocoa butter - latent chg of fusion
- when 1 g solid is heated and melts => heat absorbed
-
triple pt
water = 0.01 deg C and 6.04.10 atm - all 3 phases exist in equilibrium - 56.558 deg c
- critical pt
- no distinction between liq and gas phase
- supercritical fluids
-
exist above critical pt
ex: CO2-30.98 degree c and 73.8atm - critical point
- no distinction between liq and gas phase