Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE MainPhysicsKinetic Theory of Gases

The average translational kinetic energy per molecule ( E ) versus absolute temperature ( T ) is plotted for three different ideal gases: Helium (monoatomic), Hydrogen (diatomic), and Methane (polyatomic). If the slopes of the resulting straight lines are m₁ , m₂ , and m₃ respectively, which of the following correctly relates these slopes?

Options

  1. Am₁ < m₂ < m₃
  2. Bm₁ = m₂ = m₃
  3. Cm₁ > m₂ > m₃
  4. Dm₁ = m₂ < m₃

Correct answer

B. m₁ = m₂ = m₃

Step-by-step solution

The average translational kinetic energy per molecule for any ideal gas, regardless of its atomicity or molar mass, is given by: E = 3 2 k_B T where k_B is the Boltzmann constant and T is the absolute temperature. This equation represents a straight line passing through the origin with a slope of 3 2 k_B . Since this slope is a universal constant for all ideal gases, the graphs for Helium, Hydrogen, and Methane will have the exact same slope. Therefore, m₁ = m₂ = m₃ . Answer: m₁ = m₂ = m₃

Practice Kinetic Theory of Gases on Quantrex Academy →

More from Kinetic Theory of Gases

If 2 mole of an ideal monoatomic gas at temperature T , is mixed with 6 mole of another ideal monoatomic gas at temperature 2T then the temperature of mixture is : 2026Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Statement I: Change in internal energy of a system containing n mole of ideal g 2026Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A: If the average kinetic energy of H₂ and O₂ molecules, kept in two 2026One gas of n₁ mole of molecules at temperature T₁ , volume V₁ , and pressure P₁ , and another gas of n₂ mole of molecules at temperature T₂ , volume V₂ , and pressure P₂ , are mixe 2026A mixture of carbon dioxide and oxygen has volume 8310 cm ^3 , temperature 300 K, pressure 100 kPa and mass 13.2 g. The number of moles of carbon dioxide and oxygen gases in the mi 2026The mean free path of a molecule of diameter 5 10⁻¹⁰ ~m at the temperature 41^ C and pressure 1.38 10⁵ ~Pa , is given as _ _ _ _ m. (Given k_ B =1.38 10⁻²³ ~J / K ). 2026A gas of certain mass filled in a closed cylinder at a pressure of 3.23 kPa has temperature 50^ C . The gas is now heated to double its temperature. The modified pressure is _ _ _ 2026Consider two boxes containing ideal gases A and B such that their temperatures, pressures and number densities are same. The molecular size of A is half of that of B and mass of mo 2026 Full Kinetic Theory of Gases list All JEE Main PYQs