Read the given statements and decide which is/are correct on the basis of kinetic theory of gases.
- Energy of one molecule at absolute temperature is zero.
- The rms speeds of different gases are same at same temperature.
- For one gram of all ideal gases kinetic energy is same at same temperature.
- For one mole of all ideal gases' mean kinetic energy is same at same temperature
Answer & explanation
Correct answer: option 3
- If the gas is not ideal then its molecule will possess potential energy. Hence, statement (I) is wrong.
- The rms speed of different gases at same temperature depends on its molecular weight (\(v_{rms} \propto \frac{1}{\sqrt{M}}\)). Hence, statement (II) is also wrong.
- Kinetic energy of one gram gas depends on the molecular weight (\(E_{gm} \propto \frac{1}{M}\)). Hence, statement (III) is also wrong.
- But KE of one mole of ideal gas does not depend on the molecular weight (\(E = \frac{3}{2}RT\)). Hence, (IV) is correct.