L30S07_Equi_Temp_Lechatelier 04-04-07

L30S07_Equi_Temp_Lechatelier 04-04-07 - Chem 1A, L30:...

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Unformatted text preview: Chem 1A, L30: "Equilibrium, Temp, LeChatelier" Equilibrium Phase Change H2O (l) H2O (g) Gas Phase 2 NO2 (g) Law of Mass Action aA+bB cC+dD [C]c [D]d Products Previously Pi N2O4 (g) (g H3O+ (aq) + Ac (aq) AgCl (s) aA+bB cC+dD Reaction Q= = K(T) at Equ. Quotient Reactants [A]a [B]b Q<K [Xi] L17-4 Aqueous HAc (aq) + H2O (l) aq) Heterogeneous Ag+ (aq) + Cl- (aq) A.Pines,M.Kubinec Products A.Pines,M.Kubinec Q=K EQUILIBRIUM Q>K Reactants L17-5 Vapor Pressure of Water P Equilibrium Approach and Maintenance H2,O2 Unstable H2O (l) equ. equ. H2O (g) Pvap P V L G T Monotonic A.Pines,M.Kubinec Q = PH2O = Pvap(T) = K H2O (g) equ. equ. Stable Pi, [Xi] Stable H 2O H2O (l) Pvap S Q = 1/PH2O = 1/ Pvap(T) = K' 1/P UC 2001Regents A.Pines,M.Kubinec,UCB Clock Oscillatory L24-6 Chaotic L30-1 L17-10 Effect of P, V, T, n Equilibrium Le Chtelier's Principle A system in equilibrium subjected to a stress will react in a direction that tends to reduce the stress Q=K Q>K Q=K V P Q Summary Q= PN2O4 P2NO2 2 NO2 (g) N2O4 (g) At 25 C, K ~ 6.8, H = -57.2 kJ mol-1 = K at Equilibrium (T) L18-4 A.Pines,M.Kubinec.UCB L18-5 A.Pines,M.Kubinec.UCB Ammonia Synthesis (Haber-Bosch 1910) (HaberN2 (g) + 3 H2 (g) H ~ -92 kJ 2 NH3 (g) mol-1 Raise P Multiple Equilibria A H1 K1 B B H2 K2 C = [C] [A] A H3 K3 C Slow at 25o C. High T means low K: K3 = [C][B] ][B [A][B] ][B = K1 K2 Actual Conditions: T~ 500 oC P~ 200 atm L18-9 H3 = H1 + H2 A.Pines,M.Kubinec.UCB L18-10 A.Pines,M.Kubinec.UCB Effect of P, V, T, n 2 NO2 (g) N2O4 (g) Equilibrium At 25 C, K ~ 6.8, H = -57.2 kJ mol-1 Exothermic Q= PN2O4 P2NO2 = K at Equilibrium (T) L30-3 2001 A.Pines,M.Kubinec,UCB A.Pines,M.Kubinec,UCB 1 Chem 1A, L30: "Equilibrium, Temp, LeChatelier" ChemQuiz 30.1 The volume is doubled by opening the valve. As the system approaches equilibrium the color intensity will ...? 1) Increase 2001 A.Pines,M.Kubinec,UCB 2) Same 3) Decrease L30-4 Le Chtelier's Principle A system in equilibrium subjected to a stress will react in a direction that tends to reduce the stress Q=K Q>K Q=K V P Q 2001 A.Pines,M.Kubinec,UCB L30-6 ChemQuiz 30.2 Which strategy can best reverse CO blood poisoning? poisoning? Hb(O2)4 + 4 CO Hb( 2 Hb(CO)4 + 4 O2 Hb( CO) L30-7 1) Increase P O 2) Cool off 3) Remove Hb 2001 A.Pines,M.Kubinec,UCB A.Pines,M.Kubinec,UCB 2 Chem 1A, L30: "Equilibrium, Temp, LeChatelier" ChemQuiz 30.3 The temperature for 2 NO2 (g) N2O4 (g) is raised. What happens to the color intensity at equilibrium? 1) Increase 2) Same 2001 A.Pines,M.Kubinec,UCB 3) Decrease L30-9 Ammonia Synthesis (Haber-Bosch 1910) (HaberN2 (g) + 3 H2 (g) 2 NH3 (g) H ~ -92 kJ mol-1 Slow at 25o C. High T means low K: Raise P Actual Conditions: T~ 500 oC P~ 200 atm L30-11 2001 A.Pines,M.Kubinec,UCB Multiple Equilibria A H1 K1 B B [ C] [A ] H2 K2 C A H3 K3 C K3 = = [C][B] ][B [A][B] ][B = K1 K2 H3 = H1 + H2 2001 A.Pines,M.Kubinec,UCB L30-12 A.Pines,M.Kubinec,UCB 3 Chem 1A, L30: "Equilibrium, Temp, LeChatelier" ChemQuiz 30.4 For the molecular rearrangement shown, how does K depend on T? K K A H1 B H2 C K 1) T 2001 A.Pines,M.Kubinec,UCB 2) T 3) T L30-13 ChemQuiz 30.5 Consider the equilibria: Ni(H20)62+ Ni(H20)62+ Ni(NH3)62+ 6 NH3 K1 3 en K3 en en NH3 Ni(NH3)62+ Ni(en)32+ What is the color of K2 ? Ni(en)32+ 1) Blue 2001 A.Pines,M.Kubinec,UCB 2) Violet 3) Can't tell Can' L30-15 Lecture Complete 2001 A.Pines,M.Kubinec,UCB L30-17 A.Pines,M.Kubinec,UCB 4 ...
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