# What is the mean free path of gas?

## What is the mean free path of gas?

In the kinetic theory of gases, the mean free path of a particle, such as a molecule, is the average distance the particle travels between collisions with other moving particles.

**What is the formula for mean free path?**

Mathematically the mean free path can be represented as follows: λ = 1 2 π d 2 N V. Let’s look at the motion of a gas molecule inside an ideal gas, a typical molecule inside an ideal gas will abruptly change its direction and speed as it collides elastically with other molecules of the same gas.

### What does the mean free path of a molecule in a gas depend on?

The mean free path equation depends upon the temperature and pressure as well as the molecular diameter.

**Which factors affecting mean free path?**

Solution

- Mean free path increases with increasing temperature.
- It is the reason why the smell of hot sizzling food reaches several metres away from the smell of cold food.
- The mean free path increases with decreasing pressure of the gas and the diameter of the gas molecules.

## What factors mean free path depends?

The factors on which the mean free path (λ) of a gas molecule depends are: (i) Diameter of the molecule: (ii) Number of gas molecules per unit volume: (iii) It depends indirectly on factors like temperature, pressure and Boltzmann constant.

**Why is mean free path important?**

The reason for this lies in the great number of collisions that a gas particle sustains along its way. The mean free path is the average distance that a particle can travel between two successive collisions with other particles….1.2. 5 Mean free path.

ˉl | Mean free path | [m] |
---|---|---|

m | Mass | [kg] |

### On what factors does the mean free path depend?

Mean free path is influenced by the density, radius of the molecule and also pressure and temperature. As the pressure increases the mean free path decreases.

**How do mean free path of gas depend on temperature?**

So, as the temperature increases → the Kinetic energy of the molecules increases → the Faster motion of molecules takes place within a similar time interval. It will augment the mean free path of the molecules in a gas sample. It will reduce the mean free path of the molecules in a gas sample.

## How does mean free path depend on temperature and pressure?

The mean free path or average distance between collisions for a gas molecule may be estimated from kinetic theory. Mean free path displays linear proportionality to the temperature and inverse proportionality to the pressure and molecular diameter. Mathematically it is expressed as: l. p= πdkT.