CHEMISTRY · Single correct · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
For the reaction 2NO2 (g) ⇌ N2O4 (g), a student’s particulate diagram shows only N2O4 molecules in the container. Which of the following best explains why this diagram does NOT depict a system at equilibrium?
(a) Because the balanced equation contains a 2 : 1 coefficient ratio, the container should display twice as many NO2 molecules as N2O4 at equilibrium.
(b) A correct equilibrium diagram must show equal numbers of NO2 and N2O4 particles.
(c) Both NO2 and N2O4 must be present because the forward and reverse reactions occur simultaneously at equilibrium.
(d) At equilibrium the reaction stops, so a correct diagram would show no further collisions or molecular changes.