Kinetic Theory

JEE Main level, single correct, medium

129 of 168

Question 129 of 168

A gas mixture consists of 88 moles of argon and 66 moles of oxygen at temperature TT. Neglecting all vibrational modes, the total internal energy of the system is

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Answer: (C) 27RT27RT

As we know, internal energy is given by, U=nCvTU=n{C}_{v}T. Also argon gas is monoatomic and oxygen gas is diatomic.
Therefore, total internal energy will beUnet=n1CV1T+n2CV2T{U}_{net}={n}_{1}{C}_{{V}_{1}}T+{n}_{2}{C}_{{V}_{2}}T
=8×3R2×T+6×5R2×T=8\times \dfrac{3R}{2}\times T+6\times \dfrac{5R}{2}\times T
=27RT=27RT

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