contains the maximum amount of solute that will dissolve in a given solvent at a specific temperature
unsaturated solution
contains less solute than it has the capacity to dissolve
supersaturated solution
contains more solute than is present in a saturated solution, can be formed by careful cooling, solute will separate if solution is disturbed (crystalization)
solubility
the measure of how much solute will dissolve in a solvent at a specific temperature
"like dissolves like" - 2 substances with intermolecular forces of similar type and magnitude are likely to be soluble in each other
(non-polar will be soluble with non-polar) hydrocarbons are always non-polar
(polar w polar)
miscible
if substances are completely soluble in each other in all proportions
concentration
the amount of solute present in a given amount of solution
molarity
M = mol solute/ L solution
percent by mass
mass of solute/mass of solution * 100%
mole fraction
mol of single component/moles of all components
Xa has no units
molality
m = moles of solute/mass of solvent (kg)
solvation
the process in which an ion or molecule is surrounded by solvent molecules arranged in a specific manner
fractional crystallization
the separation of a mixture of substances into pure components on the basis of their differing solubilities
The effect temperature has on the solubility of a solid
usually solubility increases but there are exceptions, it is best determined experimentally
The effect temperature has on a gas solute
solubility usually decreases with increasing temperature
warm water is bad for fishes because the solubility of oxygen decreases
Henry's law
the solubility of a gas in a liquid is proportional to the pressure of the gas over the solution
c =kP
if more than 1 gas present P = partial pressure
c = molar concentration
Effect of pressure on solubility
doesn't change with liquids or solids
external pressure GREATLY INCREASES the solubility of gas
colligative properties
(or collective properties) - properties that depend only on the # of solute particles in solution and not on the nature of the solute particles
1. vapor-pressure lowering
2. boiling-point elevation
3. freezing-point depression
4. osmotic pressure (raising)
electrolyte vs. nonelectrolyte
electrolytes break apart into ions when they dissolve
nonelectrolytes do not break apart (molecular compounds or covalent compounds that aren't acids and bases)
vant hoff factor
i - actual # of particles in soln after dissociation/# of formula units initially dissolved in solution
used to convert from concentration of solute to particles
nonelectrolytes i = 1
ion pair
one or more cations and one or more anions held together by electrostatic forces
nonvolatle
does not have a measurable vapor pressure
the vapor pressure of a nonvolatile solution is always less then that of the pure solvent
Raoult's law
P1 = X1 P1*
X is mole fraction of the solvent not solute
P1 is vapor pressure of solution
P1* is vapor pressure of pure solvent
DONT USE i
volatile
has measurable vapor pressure
do Raoult's law to each substance with measureable vapor pressure
total pressure is sum of partial pressures
boiling point
the temperature at which the vapor pressure equals the external atmospheric pressure
^ Tb = Kb im
im = concentration of particles in molality
^ Tb = Tb - Tb*
freezing point
adding solute lowers it
freezing point depression
^Tf = Tf* - Tf
^Tf = Kf im
osmotic pressure
the pressure required to stop osmosis (the selective passage of solvent molecules through a porous membrane from a dilute solution to a more concentrated one)
(cap pie) = iMRT
M is molarity of particles
ideal solution
any solution that obey's Raoult's law
fractional distillation
a procedure for separating liquid components of a solution based on their different boiling points
isotonic solution
two solutions of equal concentration, therefore equal osmotic pressure
hypotonic solution
unequal concentrations - this is the more dilute solution
hypertonic solution
unequal concentrations - this is the more concentrated solution
colloids
a dispersion of particles of one substance throughout a dispersing medium made of another substance (not really a solution) does not break apart over time