Explain, using the kinetic model of an ideal gas, why two identical containers holding the same mass of gas but at different temperatures exert different pressures on their walls, and identify which container exerts the greater pressure.

At a given volume and amount of gas the pressure is proportional to the average kinetic energy of the molecules. In the kinetic model the average kinetic energy per molecule is ½mv² and is directly proportional to the absolute temperature (E_avg=3/2kT). Therefore the gas in container B, at 600 K, has a higher average kinetic energy and its molecules move faster than those in container A at 300 K.

Because the molecules in B move faster, each collision with a wall transfers a larger momentum change, giving a greater force per collision. Moreover, the higher speed means collisions occur more frequently per unit area per unit time. Both the larger force per collision and the higher collision frequency increase the pressure.

Thus, container B exerts the greater pressure on its walls, in accordance with Gay‑Lussac’s law (P∝T at constant V and n).