A reactor is used to produce hydrochloric acid by feeding hydrogen and chlorine gases into the reactor. The reaction occurring in the reactor is given as follows: H2 (g) + Cl2 (g) 2 HCl (g) The flow rates of hydrogen and chlorine gases fed into the reactor are 10.0 kg/h and 280.6 kg/h, respectively, at 25C, and the product gas mixture exits the reactor at 500C. Calculate the enthalpy change in the reactor.