Question

73. Consider the reaction:

CO(g) + 2H2(g) <--> CH3OH(g) Kp= 2.26X10E4 at 25 C

Calculate ΔG^o_rxnfor the reaction at 25C under each of the following conditions:

a. standard conditions

b. at equilibrium

c. P_CH3OH= 1.0 atm; P_CO= P_H2 = 0.010 atm

Answer 1

a. ^o_rxn = - RTlnK_p [ T = 25^oc = 298K]

= -8.314*298*ln(2.26*10⁴)

= - 2477.57*10.02

= - 24839.4 J = - 24.839KJ

b. At equilibrium, ^o_rxn = 0. ( k_p​​​​​​= 1)

C.

For the given reaction K_p = P(CH₃OH)/ P(CO) *P²(H₂)

= 1/(0.010)*(0.010)²

= 10⁶

Then, ^o_rxn = - RT lnK_p

= - 8.314*298ln(10⁶)

= - 2477.57*13.81

= -34228.9 J

= - 34.22 KJ