Question

The equilibrium system N2O4(g) 2NO2(g) was established in a 1.00-liter vessel. Upon analysis, the following information was found: [NO2] = 0.500 M; [N2O4] = 0.0250 M. What is the value of Keq?
a. 20.
b. 0.050
c. 10.0
d. 0.10

Answer 1

Answer: c)  10.0

Explanation:

The balanced equilibrium reaction will be,

$N_2O_4(g)\rightleftharpoons 2NO_2(g)$

Concentration of $NO_2$ at equilibrium = 0.500 M

Concentration of $N_2O_4$ at equilibrium  = 0.0250 M

The expression for equilibrium reaction will be,

$K_{eq}=\frac{[NO_2]^2}{[N_2O_4]}$

Now put all the given values in this expression:

$K_{eq}=\frac{(0.500)^2}{(0.0250)}$

$K_{eq}=10.0$

Therefore, the equilibrium constant is 10.0.

Answer 2

For the reaction, the equilibrium constant equation will be:

Kc = [NO₂]² / [N₂O₄]
Kc = (0.5)² / 0.025
Kc = 10

The answer is C.