Le Chatelier's principle states that if a system at equilibrium is subjected to a change in temperature, pressure, or concentration of reactants or products, the system will adjust its equilibrium position to counteract the change.For the reaction: 2NO2 g N2O4 g 1. Effect of temperature:The reaction is exothermic releases heat in the forward direction, as the formation of N2O4 from NO2 releases heat. When the temperature is increased from 25C to 100C, the system will try to counteract the increase in temperature by shifting the equilibrium towards the endothermic absorbs heat direction. In this case, the endothermic direction is the reverse reaction breaking N2O4 into NO2 . Therefore, the equilibrium will shift to the left, favoring the formation of NO2.2. Effect of pressure:When the pressure is decreased from 1 atm standard pressure to 0.5 atm, the system will try to counteract the decrease in pressure by shifting the equilibrium towards the side with more gas molecules. In this reaction, there are 2 moles of NO2 gas on the left side and 1 mole of N2O4 gas on the right side. Therefore, the equilibrium will shift to the left, favoring the formation of NO2.In conclusion, when the temperature is increased to 100C and the pressure is decreased to 0.5 atm, the equilibrium of the reaction will shift to the left, favoring the formation of NO2.