Question

Methanol (CH3OH) is produced commercially by the catalyzed reaction of carbon monoxide and hydrogen: CO(g)+2H2(g)←−→CH3OH(g). An equilibrium mixture in a 1.50 −L vessel is found to contain 7.17×10−2 mol CH3OH, 0.170 mol CO, and 0.301 mol H2 at 500 K.

Calculate Kc at this temperature.

Answer 1

molarity of CO = 0.170 / 1.50 = 0.113 M

molarity of H2 = 0.301 / 1.50 = 0.201 M

molarity of CH3OH = 7.17 x 10^-2 / 1.50 = 0.0478

CO + 2H2 <--------------------------> CH3OH

0.113 0.201                                    0.0478 --------------> equilibrium

Kc = [CH3OH] / [CO] [H2]^2

Kc = 0.0478 / 0.113 x (0.201)^2

Kc = 10.47