Consider the following reaction between acetylene and water: C_2 H_4 (g) + 3 O_2 (g) rightarrow 2 CO_2 (g) + 2 H_2 O(l) a. Provide the reaction quotient expression: b. Determine delta_r S degree. c. Determine delta_r S given P(C_2 H_4) = 0.60 bar, P(CO_2) = 1.00 bar, and P (O_2) = 645 mmHg?
Expert Answer
Answer
reaction quotient Qp = P[CO2]2/P[O2]3*P[C2H4] , H2O is not considered as liquid has no pressure
P[CO2] = 1 bar , P[O2] = 645*1.01325/760 = 0.86 bar , P[C2H4] = 0.6 bar T=25oC = 298 K
dG = -2.303RTlogQp = -2.303*8.314*298 log(1)2/(0.86)3*(0.6) = 2387J/ mol
dS = dG/T = 2387/298 = 8.011 J/mol/K