CHEM 1125Q 1st Edition Lecture 11 Outline of Last Lecture Ch. 13I. Solutions, Solvation, Entropy, Molarity, Molality, Percent by MassOutline of Current Lecture Ch. 13II. SolubilityA. Henry’s LawIII. Colligative PropertiesIV. Raoult’s LawV. Boiling Point Elevation and Freezing Point DepressionA. Boiling Point ElevationB. Freezing Point DepressionCurrent LectureII. SolubilityA. Henry’s Lawa. Solubility is affected by many factors, such as temperature and pressureb. Henry’s Law states that the solubility of a gas in a liquid is proportional to the pressure of the gas over solutioni. C = KPC = molar concentration (mol/L)K = constant (mol/L atm)P = pressure (atm)III. Colligative PropertiesA. Colligative properties are properties that depend on the concentration of solute particles in a solution instead of on the nature of the particles dissolvedB. Properties that arise from the vapor pressure lowering include:a. Boiling point elevation (molality)b. Freezing point depression (molality)c. Osmotic pressure (molarity)IV. Raoult’s LawA. Raoult’s Law states that the partial pressure of a solvent over a solution is given by the vapor pressure of the pure solvent times the mole fraction of thesolvent in the solutionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a. Raoult’s Lawi. P1 = X1P10 ΔP = X2P10P1 = Partial pressure of solvent over solutionX1 = Mole fraction of solventP10 = Vapor pressure of pure solventΔP = P10 – P1X2 = Mole fraction of soluteb. If both compounds in a solution are volatile, then a solution’s vapor pressure is the sum of the individual partial pressuresi. PA = XAPA0PB = XBPB0PT = XAPA0 + XBPB0 Ideal solutions obey Raoult’s LawV. Boiling Point Elevation and Freezing Point DepressionA. Boiling Point Elevationa. Solutions boil at higher temperatures than pure solvents. Therefore, adding solute to a solvent raises its boiling pointi. ΔTB = TB – TB0ΔTB = KBmΔTB = Boiling point elevationKB = Boiling point elevation constantm = molalityB. Freezing Point Depressiona. Solutions freeze at lower temperatures than pure solvents. Therefore, adding solute to a solvent lowers its freezing pointi. ΔTF = TF – TF0ΔTF = KFmΔTF = Boiling point elevationKF = Freezing point elevation constantm =
View Full Document
Unlocking...