A helium atom is two times heavier than a hydrogen molecule. At 298 K, the average kinetic energy of a helium atom is:
Correct answer: D. The same as a hydrogen molecule
- A. Two times less than a hydrogen molecule
- B. Two times that of a hydrogen molecule
- C. Four times that of a hydrogen molecule
- D. The same as a hydrogen molecule
Explanation
According to the kinetic theory of gases, the average translational kinetic energy of gas particles depends only on the absolute temperature (K.Eavg = 3/2 kT). Since both are at the same temperature, their average kinetic energies are the same, regardless of their mass .
Last updated
About Kinetic Molecular Theory
Kinetic molecular theory explains gases as rapidly moving particles separated by large distances, with negligible volume and negligible intermolecular attraction in the ideal model. It relates temperature to average kinetic energy and explains gas pressure, Boyle's and Charles's laws, diffusion, effusion and the conditions under which real gases deviate from ideal behavior.
Practise Gases
443 free Gases MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A balloon filled with ethyne is pricked with a sharp pointed needle and quickly dropped in a tank of H2 gas under identical conditions. After a while the balloon will be:
A bottle of dry NH3 and a bottle of dry HCI connected through a long tube are opened simultaneously of both ends. The white NHCl ring formed will be
A fixed mass of an ideal gas is contained in a cylinder at a constant temperature. Now, the pressure of the gas is decreased. What happened to the molecules of gas?
A gas diffuses 1/2 times as fast as hydrogen, its molecular mass is:
A gas sample contains three molecules each having speeds 1 ms-1, 2 ms-1, and 3 ms-1. What is the mean square speed?