Question

10. The rotational kinetic energy of two moles of
monatomic gas at 27°C is equal to
(1) 400 R
(2) 1200 R
(3) 300 R
(4) Zero​

Answer 1

It's too simple dear,

It's a class 5th question,

Do yourself,

Translational kinetic energy =

It's 3/2 RT

so,

Here translational = 3/2*R*300 = 450 R

But in mono atomic gas there is no rotation about any axis

For example, He gas can't rotate!

But H2 gas can rotate about bond axis,

So for mono atomic gas rotational kinetic energy is always zero at any temperature and for any mono atomic gas

So your answer is zero

Also vibrational kinetic energy is zero but it's not in syllabus

Answered by an IIT JEE ASPIRANT and all India mathematics OLYMPIAD TOPPER in class 10th