Question

For the reaction: ch3oh(g) ⇌ co(g) + 2h2(g), with the equilibrium concentrations for [ch3oh]=0.20 m, [co]=0.44 m, and [h2]=2.7 m, determine the gas phase equilibrium constant (kp) at 400 0c?

Answer 1

The concentration equilibrium constant is calculated as:
Kc = [CO][H2]^2 / [CH3OH] = (0.44 M)(2.7 M)^2 / (0.20 M) = 16.038 M^2
The degree of the reaction is the sum of the product coefficients minus that of the reactants: n = 1 (CO) + 2 (H2) - 1 (CH3OH) = 2
Then the pressure equilibrium constant is calculated as:
Kp = Kc*(RT)^(n) = (16.038 M^2)*[(0.08206 atm/M-K)(673.15 K)]^(2) = 48,936.95 atm^2
Remember to use absolute temperature of 400+273.15 K, not the 400 C itself.