Chem 130 Chp. 15

Chp. 15 Chemical rest Occurs when a reaction and its reverse reaction (opposing reactions) cash in ones chips at the same rate At symmetricalness the rate at which products are produced from reactants equals the rate at which reactants are produced from products At equilibrium a particular ratio of concentration terms equals a constant The written report of an equilibrium mixture does not change with time Kc equilibrium constant 15. 2 Law of mass action expresses the relationship in the midst of the concentrations of the reactants and products present at equilibrium 5. 3 * * LARGE VALUE OF Kc Equilibrium mixture contains more products than reactants = product lieu (right side) K 1 *SMALL VALUE OF Kc Equilibrium mixture contains less products than reactants = reactant side (left side) K 1 The equilibrium-constant expression for a reaction written in one direction is the reciprocal of the one for the reaction written in the reverse direction Multiplying all the stoichiometric c oefficients by a matter gives the equilibrium constant for the original reaction raised to that number 15. 4Concentrations of subtile SOLIDS and LIQUIDS DO NOT appear in equilibrium expression L S 15. 5 ICE TABLS 15. 6 15. 7 Le chateliers convention IF a system at equilibrium is disturbed by a change in temperature, pressure, or the concentration of one of the components, the system go away shift its equilibrium position so as to counteract the proceeding of the disturbance % of NH3 at equilibrium decreases with increasing temperature and attachs with increasing pressure * * energy-absorbing reaction increase in temperature shifts equilibrium to right reactant bsorbs heat change magnitude T results in an increase K * Exothermic reaction Temperature increase shifts equilibrium to left product gives off heat Increasing T results in decreasing K * * Increasing pressure ( decreasing volume) equilibrium shifts in the direction producing the smaller number of moles of gas will fo reshorten the pressure * * Decreasing pressure (increasing volume) equilibrium shifts in the direction producing the larger number of moles of gas produces more pressure