Chemistry 11600 Fall 2014 Learning Objectives for Equilibrium: The Extent of Chemical Reactions ! To describe the difference between “completion” for irreversible chemical reactions and for reversible chemical reactions. ! To describe a system at chemical equilibrium. ! To describe the “position” of equilibrium. ! To describe the law of chemical equilibrium (law of mass action). ! To write an equilibrium constant expression for a reversible reaction in terms of reactant and product concentrations or partial pressures (gases). ! To calculate the value of the equilibrium constant for a reversible chemical reaction given the equilibrium concentrations of all reactants and products. ! To describe why the concentrations of the reactants and products do not change when a chemical reaction has reached equilibrium. ! To describe chemical equilibrium in terms of the rates of the forward and reverse reactions. ! To describe what information is provided by the value of the equilibrium constant for a chemical reaction. ! To calculate the value of Kp given the value of Kc (and vice versa). ! To calculate the value of the reaction quotient, Q, given the concentrations or partial pressures (gases) of reactants and products at any moment in time. ! To describe how the value of the reaction quotient at any moment in time can be used to: ! determine whether or not a chemical reaction is at equilibrium. ! determine in which direction the chemical reaction must proceed to reach equilibrium. ! To describe two sets of conditions where a chemical reaction can reasonably be treated as an irreversible reaction (i.e., single arrow). ! To describe LeChatelier’s principle. ! To describe the effect(s) on a system at chemical equilibrium when each of the following is changed: ! concentration (either reactants or products) ! pressure (amounts of either reactants or products; addition of an inert gas; volume of the container) ! temperature (reaction enthalpies) ! To calculate the new equilibrium position attained when a change in concentration of either a reactant or product is made to a system initially at equilibrium. ! To describe and use the van’t Hoff equation. Chemistry 11600 Fall 2014 ! To describe the interplay between the rate of reaction and the magnitude of the equilibrium constant for reversible chemical reactions. ! To describe the “Haber-Bosch Process” and how the experimental conditions were chosen to maximize the yield of ammonia. ! To describe the effect of a catalyst on the equilibrium position for a reversible chemical reaction. 2.