 During the dissolving process the solvent and solute go from a state of order, separate and particles arranged regularly, to a state of disorder.  Solvation: the process in which an ion or molecule is separated from other parts of the solute and surrounded by the particles of the solvent.  Hydration: the name given to solvation when water is the solvent.  If two substances are completely soluble with one another they are said to be miscible.  Two substances which will not mix are immiscible.

Percent by Mass % by mass = mass of solute Mass of solute + mass of solution

Mole Fraction (X) X A = moles of A Sum of all moles in mixture

Molarity (M) M=moles solute Volume of solution (L)

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

 Temperature and Solubility  Recall:solubility is the amount of solute dissolved by a given amount of solvent at a specific temperature.  In most cases, solubility increases as temperature increases. However, this is not always the case and solubility is best determined experimentally.  Fractional Crystallization: the separation of a mixture of substances into pure components on the basis of their differing solubility.

 Pressure and Solubility  Henry’s Law: › the solubility of a gas in a liquid is proportional to the pressure of the gas over the solution.

 Properties that depend on the number of solute particles in solution and not on the nature of the solute particles.

Vapor-Pressure Lowering  The vapor pressure of a solution with a non- volatile solute will always be lower then the pure solvent.  Raoult’s Law :Vapor pressure over a solvent over a solution is equal to the product of the mole fraction of the solvent in the solution and the vapor pressure of the pure solvent.  Fractional distillation:a procedure for separating liquid components of a solution based on their different boiling points.

Boiling-Point Elevation  Since a nonvolatile solute will decrease the vapor pressure of the solvent which results in raising the boiling point of the solution above that of the pure solvent.  T b = T b -T b o  This can be determined by multiplying the molality of the solution by a constant which is determined by the identity of the solvent.  T b = K b m

Freezing-Point Depression  The lowering of the vapor pressure is also responsible for the lowering of the freezing point of a solution below that of the pure solvent.  T f = T f o - T f  Like the Boiling-Point Elevation, the Freezing – Point Depression can be determined by multiplying the molality of the solution by a constant value.  T f = K f m