Kinetic Theory Of Gases Question 152
Question: A vessel contains a mixture of one mole of oxygen and two moles of nitrogen at 300 K. The ratio of the average rotational kinetic energy per $ O _{2} $ molecule to that per $ N _{2} $ molecule is
Options:
A) 1 : 1
B) 1 : 2
C) 2 : 1
D) Depends on the moments of inertia of the two molecules
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Average kinetic energy per molecule per degree of freedom (300 K), since both the gases are diatomic and at same temperature (300 K), both will have the same number of rotational degree of freedom i.e. two.
Therefore, both the gases will have the same average rotational kinetic energy per molecule $ ( =2\times \frac{1}{2}kT=kT ) $ Thus $ \frac{E _{1}}{E _{2}}=\frac{1}{1} $