Question

At 1000 K, the value of K_c = 0.032 for the reaction:

C_(s) + H₂O_(g) ⟺ CO_(g) + H_2(g)

Calculate the equilibrium concentrations of H₂O, CO, and H₂ in a reaction mixture obtained by heating 6.05 mol of (H₂O) steam and excess of solid carbon in a 5.90 L container.

Answer 1

Initial concentration of H₂O is = Number of moles / volume in L

                                           = 6.05 mol / 5.90 L

                                           = 1.025 M

                              C_(s) + H₂O_(g) ⟺ CO_(g) + H_2(g)

initial conc                       1.025         0          0

change                             -a            +a         +a

Equb conc                   1.025-a          a          a

Equilibrium constant , K_c = ([CO][H₂]) / [H₂O]                         Concentration solids cannot be considered.

                           0.032 = ( a x a ) / (1.025 - a )

Solving we get a = 0.166 M

So Equilibrium concentration of H₂O = 1.025-a = 1.025 - 0.166 = 0.859 M

Equilibrium concentration of CO = a = 0.166 M

  Equilibrium concentration of H₂ = a = 0.166 M