AP Chem term (Ch. 11) | Definition |
molarity (M) | moles of solute per kilogram of solvent in a solution. |
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 (m) | 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 reactions. |
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 solvent present. |
colligative properties | properties of a solution that depend only on the number, and not on the identity, of the solute particles (concentration). |
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 (pi) | the pressure that must be applied to stop osmosis. |
dialysis | a phenomenon in which a semipermeable membrane allows transfer of both solvent molecules and small solute molecules and ions. |
isotonic solutions | 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 of to the solvent. |
desalination | the removal of dissolved salts from an aqueous solutions. |
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 deduction of a colloid by causing particles to aggregate and settle out. |