Can a gas become incompressible at any given pressure and constant volume?

 Can a gas become incompressible at any given pressure and constant volume?

Answer

Gas molecules inside a volume (e.g. a balloon) are constantly moving around freely. During this molecular motion they frequently collide with each other and with the surface of any enclosure there may be (in a small balloon that would be many thousands of billions of collisions each second).

Figure 1: The internal gas pressure in a balloon P , B

is given by the impacts of moving gas molecules, as they collide with the skin of the balloon from the inside.

And the force of impact of a single one such collision is too small to be sensed. However, taken all together, this large number of impacts of gas molecules exerts a considerable force onto the surface of the enclosure- the gas pressure .

The larger the number of collisions per area of enclosure, the larger the pressure:

The SI-unit of pressure is Pascal [Pa], but in Meteorology it is accepted to use millibars [mb], where 100 kPa = 1000 mb.

The direction of this gas pressure force is always perpendicular to the surface of the enclosure at every point.