Kinetic Theory

JEE Main level, single correct, medium

79 of 168

Question 79 of 168

A gas mixture consists of 22 moles of oxygen and 44 moles of neon at temperature TT. Neglecting all vibrational modes, the total internal energy of the system will be:

Show answer and solution

Answer: (A) 11RT11RT

The internal energy of a gas is given by U=nCVTU=n{C}_{V}T.
A diatomic gas has 33 translational and 22 rotational degrees of freedom. A monoatomic gas has 33 translational degrees of freedom.
Hence, the internal energy of the mixture =n1CV1T+n2CV2T={n}_{1}{C}_{{V}_{1}}T+{n}_{2}{C}_{{V}_{2}}T
=2×(5R2)T+4×3R2T=5RT+6RT=2\times \left(\dfrac{5R}{2}\right)T+4\times \dfrac{3R}{2}T =5RT+6RT
=11RT=11RT

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Kinetic Theory (Degree of Freedom and Specific Heat), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.