Final answer:
The student's question discusses the reversible equilibrium reaction of dinitrogen tetroxide decomposing into nitrogen dioxide. The colors of the gases provide visual evidence of this equilibrium, which is influenced by temperature and pressure following Le Chatelier's principle.
Step-by-step explanation:
Dinitrogen Tetroxide and Equilibrium
Dinitrogen tetroxide (N₂O₄) partially decomposes to form nitrogen dioxide (NO₂), a process that is represented by the equilibrium reaction N₂O₄ (g) ⇌ 2 NO₂ (g). This decomposition is color-induced as N₂O₄ is colorless and NO₂ is brown. When a container of N₂O₄ is observed, it changes color due to the formation of NO₂.
At equilibrium, the concentrations of the gases remain constant over time. The double arrow in the reaction equation indicates the reaction is reversible, moving forward to form NO₂ and backward to re-form N₂O₄ depending on the conditions such as temperature and pressure, as described by Le Chatelier's principle.
Changing temperature affects the equilibrium; for example, at lower temperatures, NO₂ converts back to colorless N₂O₄, while at higher temperatures, the NO₂ is favored. The Ideal Gas Law relates partial pressures to concentrations, allowing the relationship between N₂O₄ and NO₂ to be described quantitatively.