Solutions

Why does a raw egg swell or shrink when placed in different solutions? Chapter Objectives Define solution, solvent, solute and colligative properties and use them in calculations to solve for molality, mole fraction, weight percent and ppm Explain the differences between saturated, unsaturated and supersaturated solutions, miscible and immiscible Use lattice energy and enthalpy of hydration to explain enthalpy of solution Use Henry's law and Le Chatelier's principle to explain solubility of gases Solve problems using mole fraction, Raoult's law, and calculations predicting changes in colligative properties, and solving for variables related to colligative properties Define and calculate Osmotic pressure Driving forces for solution formation Some Definitions A solution is a HOMOGENEOUS mixture of 2 or more substances in a single phase. One constituent is usually regarded as the SOLVENT and the others as SOLUTES. 4 major topics Ways to describe solution concentrations (amount of solute per unit of solution) How and why solutions form Colligative properties (those properties that depend on the number of solute particles per solvent molecule but not on the identity of the solute) Colloids Concentration Units An IDEAL SOLUTION is one where the properties depend only on the concentration of solute. Need conc. units to tell us the number of solute particles per solvent particle. The unit “molarity” does not do this! Concentration Units MOLE FRACTION, X For a mixture of A, B, and C