Question

A 4.0L reaction flask initially contains 4.0 mol of SO₃ at 400K. Sulfur dioxide and oxygen form: 2SO₃(g) ↔ 2SO₂(g) + O₂(g). After equilibrium is established, 0.27 mol SO₃ remain. What is the value of K_c?

Answer 1

             2SO3(g) <---> 2SO2(g) + O2(g).

initial      4/4 = 1 M        0 M          0 M

change       0.9325 M        0.9325 M    0.47 M

at equili 0.27/4 = 0.0675 M 0.9325 M    0.47 M

    kC = [so2]^2[o2] / [SO3]^2

       = (0.9325^2*0.47)/0.0675^2

     Kc = 89.7