Gaseous hydrogen and chlorine at 25 ℃ enter the hydrogen chloride synthesis reactor, where they interact at 725 ℃ according to the reaction: 〖Cl〗 _2 (g) H_2 (g) = 2HCl (g). Determine the change in entropy of the system, starting from the moment the gases enter the reactor, if their volumetric flow rate is the same.