CHEM 1110 1st Edition Lecture 18Outline of Last Lecture I. The Concept of EquilibriumII. The Equilibrium Constant (K)III. Interpreting the Equilibrium Constant Outline of Current Lecture I. Equilibrium in heterogeneous II. The calculation of equilibrium III. Applications of equilibrium IV. Le Chatelier’s Principle and Equilibrium Current LectureI. Interpreting the equilibrium constant A. Summery1. Equilibrium constant expressions have products in the numerator, reactants in the denominator2. Reactions coefficients become exponents 3. Equilibrium constants are temperature dependent 4. Equilibrium constant do not have units B. Summary on reactions and K values These 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.1. K depends on direction on reaction: if reverse chemical reaction, then new K=1/K2. K changes if reaction stoichiometry changes: if multiply reaction coefficients by n, then new K=Kn3. Add two reactions and K can be combined (multiplied): combined reactions K=K1*K24. Equilibrium constants do not have units and are T dependent!II. Equilibrium in heterogeneous A. Heterogeneous equilibria: all reactants and products are not the same phase B. Concentrations are constant for pure solids and liquids in a closed system C. Kp expression only includes components that change pressure in order to achieveequilibrium III. The calculation of equilibrium A. Write equilibrium expression using known equilibrium concentrations of all components (except pure liquids or solids) and solve for KB. If only initial/final concentration of some species are known:1. Start with known initial concentrations 2. Determine changes using reactions stoichiometry3. Calculate equilibrium concentrations4. Use equilibrium concentrations or pressures and solve for K IV. Applications of equilibrium A. Uses for equilibrium constant expressions and values1. Calculating the concentration of species at equilibrium directly or using ICE method2. Predicting the overall preference of a reaction3. Predicting direction of a reaction not at equilibrium V. Le Chatelier’s Principle and Equilibrium A. Perturb system at equilibrium such Q does not equal K1. Change concentration of one species2. Change V3.Increase
View Full Document
Unlocking...