Cylinder A and Cylinder B are sealed, rigid cylinders with movable pistons. Each cylinder contains 500. milliliters of a gas sample at 101.3 kPa and 298 K. Cylinder A contains H2 and cylinder B contains N2. Explain, in terms of collisions between gas molecules and the walls of the container, why pushing the movable piston farther into cylinder B at constant temperature would increase the pressure of the N2 gas.

The pressure of N₂ gas in cylinder B when compressed at constant temperature increases due to the increase in the frequency of collision between the gas molecules with themselves and with the wall of their container caused by a decrease in volume of the container.

Explanation:

Gas helps to explain the behavior of gases when one or more of either temperature, volume or pressure is varying while the other variables are kept constant.

In the gas cylinder B, the temperature of the given mass of gas is kept constant, however, the volume is decreased by pushing the movable piston farther into the cylinder. According to the  gas law by Robert Boyle, the volume of a given mass of gas is inversely proportional to its pressure at constant temperature. This increase in pressure is due to the increase in the frequency of collision between the gas molecules with themselves and with the wall of their container caused by a decrease in volume of the container. As the cylinder becomes smaller, the gas molecules which were spread out further become more packed closely together, therefore, their frequency of collision increases building up pressure in the process.