Chem Ch 12


homogeneous mixture

saturated solution

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)


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)


if substances are completely soluble in each other in all proportions


the amount of solute present in a given amount of solution


M = mol solute/ L solution

percent by mass

mass of solute/mass of solution * 100%

mole fraction

mol of single component/moles of all componentsXa has no units


m = moles of solute/mass of solvent (kg)


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 temperaturewarm 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 solutionc =kPif more than 1 gas present P = partial pressurec = molar concentration

Effect of pressure on solubility

doesn't change with liquids or solidsexternal 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 particles1. vapor-pressure lowering2. boiling-point elevation3. freezing-point depression4. osmotic pressure (raising)

electrolyte vs. nonelectrolyte

electrolytes break apart into ions when they dissolvenonelectrolytes 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 solutionused to convert from concentration of solute to particlesnonelectrolytes i = 1

ion pair

one or more cations and one or more anions held together by electrostatic forces


does not have a measurable vapor pressurethe 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 soluteP1 is vapor pressure of solutionP1* is vapor pressure of pure solventDONT USE i


has measurable vapor pressuredo Raoult's law to each substance with measureable vapor pressuretotal pressure is sum of partial pressures

boiling point

the temperature at which the vapor pressure equals the external atmospheric pressure^ Tb = Kb imim = concentration of particles in molality^ Tb = Tb - Tb*

freezing point

adding solute lowers itfreezing 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) = iMRTM 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


a dispersion of particles of one substance throughout a dispersing medium made of another substance (not really a solution) does not break apart over timehydrophilic - water loving - proteinshydrophobic - water fearing - oil droplets