CHEM 1212 1st Edition Lecture 14 Outline of Last Lecture Practice Problems Quadratic Equation Avoiding the Quadratic Equation Outline of Current Lecture In class examples Current Lecture Ex Suppose 0 086 moles of Bromine Br2 is placed in a 1 26 L flask and heated to 1756K a temperature at which the halogen dissociates to atoms o Br2 g 2Br g o If Br2 is 3 7 dissociated at this temperature calculate Kc o Answer 3 8x10 4 o 1 reactant favored reaction Ex Consider the following equilibria involving SO2 g and their corresponding equilibrium constants o SO2 g 1 2O2 g SO3 g K1 o 2SO3 g 2 SO2 g O2 g K2 o Which of the following expressions relates K1 to K2 A K2 K12 B K22 K1 C K2 K1 D K2 1 K1 E K2 1 K12 Ex A 15 L flask at 300K contains 64 4 g of a mixture of NO2 and N2O4 in equilibrium What is the total pressure in the flask o 2NO2 g N2O4 g Kp 7 1 o Left this problem for us to solve might see it later EOC problem Ex At 2300K the equilibrium constant for the formation of NO g is 1 7x10 3 o N2 g O2 g 2NO g 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 o If the initial concentration of nitrogen gas and oxygen gas are 0 88 mol L and the initial concentration of nitrogen monoxide is 0 062 mol L what are the equilibrium concentrations of all species o Answer N2 O2 NO Left this for us to solve for practice as well in chapter example Le Chatelier s Principle o Given the reaction N2 g 3H2 g 2NH3 g H 222 6 kJ mol rxn Kc 0 16 450 C What happens when more nitrogen gas is introduced to a system already at equilibrium A Reactants are consumed and products are produced to reach a new equilibrium condition B Products are consumed and reactants are produced to reach a new equilibrium condition C Nothing changes What happens when some nitrogen gas is removed from a system already at equilibrium Same choices as above Answer B What happens when more ammonia gas is introduced to a system already at equilibrium Same choices as above Answer B What happens when the temperature is increased for a system already at equilibrium Answer B What happens when the volume is reduced for a system already at equilibrium Answer A Consider the isomerization of butane with an equilibrium constant of K 2 5 o Butane isobutene o The system is originally at equilibrium with butane 1 0M and isobutene 2 5 M o If 0 50 mol L of isobutene is suddenly added and the system shifts to a new equilibrium position what is the equilibrium concentration of butane