Question

At a certain temperature, the equilibrium constant for the following chemical equation is 2.20. At this temperature, calculate the number of moles of NO2(g) that must be added to 2.73 mol of SO2(g) in order to form 1.30 mol of SO3(g) at equilibrium.

Answer 1

                     SO2 + NO2 -------> SO3 + NO

     I              2.73      x              0     0

   C              -1.3      -1.3           1.3        1.3

   E              1.43      x-1.3        1.3          1.3

                         Kc   = [SO3][NO]/[SO2][NO2}

                         2.2   = 1.3*1.3/1.43*(x-1.3)

                          3.146x-2.86 = 1.69

                          3.146x = 1.69+2.86  

                          3.146x = 4.55

                                 x = 1.446 moles

number of moles of NO2 is 1.446