A sealed 1.0 L container at 400 K is used to study the gas-phase equilibrium
N2O4(g) ⇌ 2 NO2(g)
A student sketches a particulate diagram for the system after it has supposedly reached equilibrium. In the sketch, the container is filled with exactly 100 red–blue dumbbell particles that the student claims represent NO2 molecules. No other particles are shown.
Answer the following questions about the student’s diagram.
(1) Identify two specific misconceptions the student’s diagram reveals about chemical equilibrium for this reaction.
(2) Describe qualitatively how an accurate particulate diagram of this equilibrium mixture should differ from the student’s diagram. Be sure to reference both the identity and the relative numbers of particles present.
(3) Explain, in terms of the dynamic nature of equilibrium and the value of the equilibrium constant for this reaction, why the simultaneous presence of both N2O4 and NO2 particles is required even when the forward reaction is strongly favored.