The graph shows that the reaction is at equilibrium after 60 seconds because the concentration of both NO2(g) and N2O4(g) are:a) Increasing b) constant c) decreasing d) zero

In chemistry, the definition of a chemical equilibrium is the state in which both reactant and producs are present in costant concentrations, which means that there is not going to be neither an increase or a decrease in the concentration of any compound. Therefore the best answer that follows this description is letter B