AP Chemistry Chapter 11 Vocab - Fairchild

molarity

molarity

moles of solute per volume of solution in liters

mass percent

the percent by mass of a component of a mixture or of a given element in a compound

mole fraction

the ratio of the number of moles of a given component in a mixture to the total number of moles in the mixture

molality

the number of moles of solute per kilogram of solvent in a solution

normality

the number of equivalents of a substance dissolved in a liter of solution

enthalpy (heat) of solution

the enthalpy change associated with dissolving a solute in a solvent; the sum of the energies needed to expand both solvent and solute in a solution and the energy released from the solvent-solute interactions

enthalpy (heat) of hydration

the enthalpy change associated with placing gaseous molecules or ions in water; the sum of the energy needed to expand the solvent and the energy released from the solvent-solute interactions

Henry's Law

the amount of gas dissolved in a solution is directly proportional to the pressure of the gas above the solution

thermal pollution

the oxygen-depleting effect on lakes and rivers of using water for industrial cooling and returning it to its natural source at a higher temperature

Raoult's Law

the vapor pressure of a solution is directly proportional to the mole fraction of solvent present

ideal solution

a solution whose vapor pressure is directly proportional to the mole fraction of the solvent present

colligative properties

properties of a solution that depend only on the number, and not on the identity, of the solute particles.

molal boiling-point elevation constant

a constant characteristic of a particular solvent that gives the change in boiling point as a function of solution molality; used in molecular weight determinations

molal freezing-point depression constant

a constant characteristic of a particular solvent that gives the change in freezing point as a function of the solution molality; used in molecular weight determinations

semipermeable membrane

a membrane that allows solvent but not solute molecules to pass through

osmosis

the flow of solvent into a solution through a semipermeable membrane

osmotic pressure

the pressure that must be applied to a solution to stop osmosis; π = MRT

dialysis

a phenomenon in which a semipermeable membrane allows transfer of both solvent molecules and small solute molecules and ions

isotonic solution

solutions having identical osmotic pressures

reverse osmosis

the process occurring when the external pressure on a solution causes a net flow of solvent through a semipermeable membrane from the solution to the solvent

desalination

the removal of dissolved salts from an aqueous solution

van't Hoff factor

the ratio of moles of particles in solution to moles of solute dissolved

ion pairing

a phenomenon occurring in solution when oppositely charged ions aggregate and behave as a single particle

Tyndall effect

the scattering of light by particles in a suspension

colloid (colloidal dispersion)

a suspension of particles in a dispersing medium

coagulation

the destruction of a colloid by causing particles to aggregate and settle out