For the reactionso2(g) + no2(g) so3(g) + no(g), the equilibrium constant is 18.0 at 1,200ºc. if 2.0 moles of so2 and 2.0 moles of no2 are placed in a 20. l container, what concentration of so3 will be present at equilibrium?
a) 0.081 mol/l
b) 0.019 mol/l
c) 0.11 mol/l
d) 1.00 mol/l
e) 18 mol/l

Answer : The correct option is, (A) 0.081 mol/L

Explanation : Given,

Equilibrium constant = 18.0

Initial concentration of =

Initial concentration of =

The balanced equilibrium reaction is,

Initial conc.    0.1          0.1             0             0

At eqm.        (0.1-x)     (0.1-x)          x             x

The expression of equilibrium constant for the reaction will be:

Now put all the values in this expression, we get :

By solving the term 'x' by quadratic equation, we get two value of 'x'.

From this we conclude that, the value of x = 0.131 at equilibrium can not be more than the initial concentration. So, the value of 'x' which is equal to 0.131 M is not consider.

The concentration of at equilibrium = x = 0.081 M

Therefore, the concentration of at equilibrium is, 0.081 M

2b2t

explanation:

2b2t