Final answer:
The equilibrium concentration of N2O4 can be approximated as the initial concentration, 0.0260 M. By solving the equilibrium constant expression, we find the change in concentration (x), and hence, calculate the equilibrium concentration of NO2 to be 0.060 M.
Step-by-step explanation:
To answer the student's question about finding the equilibrium concentrations of N2O4 and NO2 in the given chemical reaction N2O4(g) ⇌ 2NO2(g), we first need to set up the expression for the reaction's equilibrium constant (Kc).
The equilibrium expression based on the reaction is Kc = [NO2]2/[N2O4]. Given Kc = 0.36 and the initial concentration of N2O4 = 0.0260 M with no initial NO2, we can define the change in concentration as x, where at equilibrium [NO2] = 2x and the changed [N2O4] = 0.0260 - x.
By substituting these into the equilibrium expression we get (2x)2/<0.0260 - x} = 0.36. This equation can be solved for x to find the concentrations at equilibrium. For simplification, if we assume x is small compared to 0.0260, then [N2O4] can be approximated as 0.0260 at equilibrium, and [NO2] as 2x. Plugging these values into the Kc expression gives x = 0.030 and [NO2] = 2(0.030) = 0.060 M at equilibrium.