Kinetic Theory Gases

One kg of a diatomic gas is at a pressure of 8 × 104 N/m2. The density of the gas is 4 kg/m3. What is the energy of the gas due to its thermal motion?

  1. 3 × 104 J
  2. 5 × 104 J
  3. 6 × 104 J
  4. 7 × 104 J

Answer

E = (5/2) nRT

= (5/2) PV

= (5/2) P (m/P)

= (5 x 8 x 104 x 1)/(2 x 4)

= 5 x 104 J

The correct option is B.