Question

Suppose a 250.mL flask is filled with 2.0mol of O2 and 1.6mol of NO . The following reaction becomes possible: N2g+O2g =2NOg The equilibrium constant K for this reaction is 0.469 at the temperature of the flask. Calculate the equilibrium molarity of N2 . Round your answer to one decimal place.

Answer 1

             N2(g)+O2(g )---------->2NOg

I         x         2 0

C -1.6    -1.6    1.6

E    x-1.6 0.4 1.6

   Kc = [NO]²/[N2][O2]

0.469 = (1.6)²/(x-1.6)(0.4)

0.469(x-1.6)(0.4) = 2.56

          0.1876x-0.30016    = 2.56

         0.1876x                 = 2.56+0.30016

        0.1876x                 = 2.86016

                  x                  =2.86016/0.1876    = 15.246 moles

[N2]   = x-1.6 = 15.246-1.6 = 13.646moles

molarity of N2 = 13.646/0.25   =54. 584M