Thermodynamics Part 2

The mean free path of molecules of an ideal gas is given as: $\lambda = \frac{V}{\sqrt{2} \pi d^{2} N}$ where : $V =$ Volume of container $N =$ No of molecules Hence with increasing temp since volume of container does not change (closed container), so mean free path is unchanged. Average collision time$= \frac{\text{ mean free path }}{V_{av}} = \frac{\lambda}{\text{avg speed of molecules}}$ $\because$ avg speed $\alpha \sqrt{T}$ $\therefore$ Avg coll. time $\alpha \frac{1}{\sqrt{T}}$ Hence with increase in temperature the average collision time decreases.