Dinitrogen tetraoxide is a colorless gas that dissociates into a nitrogen dioxide, a reddish brown gas.
N2O4 (g) ⇌ 2 NO2 (g)
An experiment was run to demonstrate that this is a dynamic equilibrium. Starting with a special form of N2O4 where one of the oxygens was isotopically labeled (18-O instead of 16-O), the system was then allowed to reach equilibrium.
Indicate with Y (yes) or N (no) which of the substances below show that the forward or reverse reactions occur for this chemical system.