Gas under pressure?

Question

When a gas is under pressure. I understand that it is the molecules moving that cause the pressure, where does this energy come from to move them, and why doesnt it die down

Answer 1

There is a constant input of energy from the environment. The kinetic motion of the molecules in the environment bumps against the molecules of the container walls. As the molecules of the container walls vibrate, this kinetic energy in turn transfers energy to the gas molecules in the container. If you put a container of gas in an environment at a temperature of absolute zero (-273 C) the pressure would die down (at least theoretically since absolute zero theoretically could not be reached) If the container is in room temperature, then there is a constant in flow of energy into the container.

Answer 2

The pressure is due to the motion of molecules. The molecules has gained energy from out side.

If the molecules give their energy to the surroundings, they are slowed down and eventually the pressure decreases.

The kinetic theory of gas explains this.

Every thing is based on the simple conservation of energy.

The energy gained by a body is equal to the energy lost by its surroundings and vice versa.

Answer 3

The kinetic molecular energy (aka energy that is moving them) are inherent properties of every molecule (at room temperature). If they were to stop moving, you would be at absolute zero ( 0 Kelvin). Theoretically they can stop moving at 0 Kelvin, which means that at Kelvin = 0 there would be no pressure at all that is exerted by the gas; however, you will find every gas molecule moving at room temperature.

Answer 4

It does die down when the temperature decreases. The kinetic energy of a gas is intimately tied to its temperature. Take a balloon and blow it up and seal it. Put it in the refrigerator or freezer. The balloon collapses because its gas' energy bas been reduced. Warm the balloon back to room temperature and the balloon will reinflate.