Constants 1 Periodic Table Part A Estimate the value of the equilbrium constant
ID: 636369 • Letter: C
Question
Constants 1 Periodic Table Part A Estimate the value of the equilbrium constant at 645 K for each of the following reactions ?G? for BrCl(g)is-1 0 kJ/mol, The standard molar entropy, S" for BrCI(g) is 240 0 J/mol-K. 2NO2(g) N,04(g). ??¡for N,01(g)is 9.16 kJ/mol, Express your answer using three significant figures You may want to reference (Pages 873-878) Section 18.10 while completing this problem Submit Reguest Answer Part B Bra(8) + Cla () 2BrCKg) AHi for BrCl(g) is 146 kJ/mol. Express your answer using three significant figures Submit Request AnswerExplanation / Answer
part A
DG0 = DH0-TDS0
DH0 = (1*DH0,N2O4)-(2*DH0,NO2)
= (1*9.16)-(2*33.2)
= -57.24 Kj
DS0 = (1*S0,N2O4)-(2*S0,NO2)
= (304.3)-(2*240.1)
= -175.9 J/K
dG0 = DH0-TDS0
T = 645 k
DG0 = (-57.24)-(645*-175.9*10^-3)
= 56.2 kj
DG0 = - RTlnK
56.2*10^3 = -8.314*645lnk
K = equilibrium constant = 2.809*10^-5
part B
DG0 = DH0-TDS0
?Hf = [1?Hf(Br2 (g)) + 1?Hf(Cl2 (g))] - [2?Hf(BrCl (g))]
= [1(30.91) + 1(0)] - [2(14.64)]
= 1.63 kJ
?S0 = [1?Sf(Br2 (g)) + 1?Sf(Cl2 (g))] - [2?Sf(BrCl (g))]
= [1(245.35) + 1(222.97)] - [2(239.99)]
= -11.66 J/K
dG0 = DH0-TDS0
T = 645 k
DG0 = (1.63)-(645*-11.66*10^-3)
= 9.15 kj
DG0 = - RTlnK
9.15*10^3 = -8.314*645lnk
K = equilibrium constant = 0.18