Question

For which condition is collision theory low?

(a) Low temperature and pressure

(b) High temperature and pressure

(c) Low temperature, high pressure

(d) High temperature, low pressure

The question was asked by my school principal while I was bunking the class.

This interesting question is from Introduction to Nonequilibrium Systems topic in chapter Properties of High Temperature Gases of Aerodynamics

Answer 1

Right option is (d) High temperature, low pressure

Best explanation: Molecular collision frequency is directly proportional to the pressure of the molecule and inversely proportional to the square root of the temperature. Therefore, for obtaining low collision frequency, the pressure should be low and the temperature should be high.