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Unformatted text preview: Sheet1 Page 1 (35 points) Using the following thermodynamic data measured at 25.0ºC, calculate the value of the equilibrium constant at 5 2 HClO(g) = O2(g) + 2 HCl(g) species: HClO(g) , O2(g) , HCl(g) DHøf(kJ/mole):-78.7 , , -92.307 Sø(J/K-mole): 236.67 , 205.138 , 186.908 The standard enthalpy of formation of gaseous diatomic oxygen is zero. DHº = 2(-92.307)+1(0)-2(78.7) = -27.2 kJ = -27200 J DSº = 2(186.908) 1(205.138) -2(236.67) = 105.614 J/K DGº = -27200 - (273.15+50)(105.614) = = -61300 J K = exp[--61300/(8.314)(323.15)] = exp(22.8) = 8 x 109 (30 points) Answer the following short essay questions: Give a full statement of the Second Law of Thermodynamics. The full statement has two parts: a) DS is path independent and b) DS is greater than or equal to zero. Predict the sign of the standard entropy change for the following reaction and briefly explain your answer. SO3(g) + H2O(g) = H2SO4(l) The entropy change is negative for two reasons: two molecules combine to form a more complex molecule and species c...
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