15.3.5 CIA Demonstration: NO2/N2O4

Question 1

CIA Demonstration: NO 2 /N 2 O 4

Answer 1

• The equilibrium between N 2 O 4 (dinitrogen tetroxide) and NO 2 (nitrogen dioxide) is endothermic.
• The equilibrium can be observed because NO 2 is brown and N 2 O 4 is colorless.

Question 2

note

Answer 2

• The equilibrium between N 2 O 4 (dinitrogen tetroxide) and NO 2 (nitrogen dioxide) is endothermic. This means that at a lower temperature reactants (N 2 O 4 ) are favored, while at a higher temperature products (NO 2 ) are favored. This process operates in accordance with Le Châtelier’s principle that if a system is in equilibrium, and a stress is applied to the system, the system will shift in such a way as to relieve the stress.
• The equilibrium can be observed because NO 2 (a common component of smog) is brown and N 2 O 4 is colorless. The positions of the equilibrium (the relative concentrations of reactants and products) at a range of temperatures can be observed as a range of colors.