Question

1a. How does kinetic molecular theory explain why pressure is directly propirtional to temperature at a fixed volume?

1b. Explain Boyle’s Law using the Kinetic Molecular Theory.

1c. A hot air balloonist is rising too fast for her liking. should she increase or decrease the temperature of the gas in the balloon?

1d. Could the pilot of the balloonist from (1c) reduce her rate of ascent by allowing some gas to leak out of the balloon?

Answer 1

1a) Gas pressure is due to the collision of gas particle with the walls of the container. We know that the average kinetic energy of a molecule directly proportional to its temperature. As a result if temperature increases the speed in which the gas molecules hit the wall increases and leads to greater collision. Finally the pressure of the system will increase.

1b) At constant temperature if there is an increase in pressure results in the expansion of a gas molecules. Because the average kinetic energy of the gas particle is increased by keeping the temperature constant it has to expand to accommodate the changes in the system. Therefore according to kinetic molecular theory at constant temperature pv= constant.

1c) If the balloon is rising too fast then the temperature of the gas in the balloon should be decreased in order to reduce its average kinetic energy. Hot air is weighs less than the same amount of cold air and the difference in density helps the balloon to rise.

1d) it is not a proper way to control the rate of ascent by allowing gas to leak out of the balloon. We can control the buoyancy by reducing the temperature of lifting gas and there by more controlled and safe journey.