Skip to content

Kinetic Theory of Gases

The molecules of an ideal gas have a range of speeds. When an individual molecule collides with another one its speed and direction changes, but as long as the temperature is constant, the distribution of speeds remains the same.The root mean square speed crms of the molecules is the square root of the mean of the squares of the speeds of all the individual molecules. If the temperature is increased, crms increases and the distribution is flatter and broader.The kinetic theory equation for an ideal gas is: pV = ⅓Nmcrms2. The mean kinetic energy of a molecule ½mcrms2 = 3/2kT where k = R/NA.

Read the text

Read the text and highlight anything you think is important. When you go on, the text is hidden and you answer from memory.

Specification: OCR Physics A (H556), A-level, 5.1.4 Ideal gases. Topic: Gases.

Key terms in this lesson

simple harmonic motion
Motion in which the acceleration of an object is proportional to its displacement from equilibrium, and is always directed towards the equilibrium position, in the opposite direction to the displacement.
restoring force
The force acting on an oscillating object that always acts towards the equilibrium position and causes the oscillation.

More in Gases

All 5 lessons in Gases · All OCR A-level Physics topics