Chapter 15, Problem 95AP

A 2.50-mol sample of $\text{NOCl}$ was initially in a 1.50-L reaction chamber at $\text{400°C}$. After equilibrium established, it was found that 28.0 percent of the $\text{NOCl}$ had dissociated:

$\text{2NOCl}\left(g\right)\underset{}{\rightleftarrows }\text{ 2NO}\left(g\right){\text{ + Cl}}_{\text{2}}\left(g\right)$

Calculate the equilibrium constant $K_c$ for the reaction.