A sealed flask contains a gaseous reaction mixture that shows no observable change in pressure over several minutes at 25 °C. Which statement most strongly supports the conclusion that the mixture is under kinetic, rather than thermodynamic, control?
a) The reaction quotient Q is equal to the equilibrium constant K at 25∘C.
b) The standard free-energy change ΔG∘ for the reaction is positive at 25∘C.
c) The calculated activation energy for the forward reaction is large compared with the thermal energy available at 25∘C.
d) The forward and reverse rate constants are equal in magnitude at 25∘C.