the kinetic regime are required. Subsequently,the intervals between sample times have to be large enough to evaluate the reaction rate at the beginning of the experiment. The time intervals between two samplings are increased with progress of the reaction since those are intended to verify the setting of the chemical equilibrium. Each sample is withdrawn from the reactor using a syringe and had a volume of 2 ml. The sulphuric acid in the samples is neutralized by adding diluted alkaline solution, and the samples are stored subcooled in order to stop the reaction