Module 4 : Kinetic Theory of Gases

Lecture 8 : Principle Of Equipartition Of Energy

Unsolved Questions

  1. A certain gas obeys the clausius equation of state p(v - b) = RT and has its internal energy given by . Show that the equation for a reversible adiabatic process is = constant.
  2. The relation between u, p, and v for many gases is of the form u = a + bpv where a and b are constants. Show that for a reversible adiabatic process = Constant where
  3. Air in a closed system expands reversibly and adiabatically from 3 MPa , 200°C to 3 times its initial volume , and then cools at constant volume until pressure drops to 1 MPa . Calculate work done and heat transfer per kg of air.
  4. A mercury atom moves in a cubical box whose edge is 1m long. Its kinetic energy is equal to the average kinetic energy of an atom of an ideal gas at 1000 K. if the quantum numbers  are nx, ny, nz all equal to n, calculate n.
  5. Show that, when ideal-gas atoms comes to equilibrium, and taking T = 300 K, P = 1000 Pa and m = 10-26 kg,  calculate
  6. Defining the average speed (w) by the equation  show that
  7. Consider a function f defined by the relation  first, differentiate partially with respect to ΩB, and then with respect to ΩA integrate twice to show
  8. The number of molecules per cubic meter at 760 mm Hg, 273 K is approximately . If the average speed of an oxygen molecule at 273 K is 450 m/s, determine the number of collisions made with the container walls per square cm per sec.
  9. Calculate the average and the rms speed s of the following groups of particles:

  10. For a neutron flux of , determine the number of neutrons per unit volume and the “partial pressure” of the neutron gas, assuming that these neutrons have a Maxwellian velocity distribution at 400 K.
  11. If a box of 1cm3 contains 105 molecules of nitrogen at 27°C having rms speed of 1000 m/s, find the pressure exerted on the walls of the container. What will be the number of collisions per m2?
  12. Show that the most probable kinetic and average energies are 1/2 kT and 3/2 kT respectively.
  13. Prove the following:
  14. Show that the number of molecules in a certain speed range is given by: