Question

If the pressure of a gas is really due to the random collisions of molecules with the walls of the container, why do pressure gauges— even very sensitive ones—give perfectly steady readings? Shouldn’t the gauge be continually jiggling and fluctuating? Explain.

Short answer

As the pressure gauges measure the average pressure exerted by the millions of molecules and atoms colliding on the walls of the container, thus there is no fluctuation on the pressure gauge.

Step-by-step solution

Given Information

Pressure of the gas is due to the random collision of molecules on the walls of the container. However, still the normal and sensitive pressure gauges do not show any fluctuation in the readings.

Finding the reason of non-fluctuation or jiggling of the pressure gauges 

The gauges that measure the pressure of the gas focuses on the macroscopic property of the element that is being taken into consideration. In case of a gas, there are millions of atoms and molecules that are colliding against the walls of the container. However, the gauge only measures the average pressure that is exerted by the millions of molecules and atoms. As a result there is no fluctuation even on a sensitive gauge.