Consider the following equation: n2o4(g) ⇄ 2 no2(g) kc = 5.8 × 10-3 if the initial concentration of n2o4(g) = 0.040 m and the initial concentration of no2(g) is 0 m, what is the equilibrium concentration of n2o4(g)?

Answer : The  concentration of at equilibrium is, 0.03977 M

Explanation :  

The given balanced chemical reaction is,

Initial conc.         0.04            0

At eqm. conc.    (0.04-x)       (2x)

The expression for equilibrium constant for this reaction will be,

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

By solving the term 'x', we get :

x = 0.00023 M

Concentration of at equilibrium = 2x M = 2 × 0.00023 = 0.00046 M

Concentration of at equilibrium = (0.04 - x) M = (0.04 - 0.00023) = 0.03977 M

Therefore, the concentration of at equilibrium is, 0.03977 M