Kinetic Theory - Result Question 24

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24. A gas mixture consists of 2 moles of $O_2$ and 4 moles of Ar at temperature T. Neglecting all vibrational modes, the total internal energy of the system is :-

======= ####24. A gas mixture consists of 2 moles of $O_2$ and 4 moles of Ar at temperature T. Neglecting all vibrational modes, the total internal energy of the system is :-

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/kinetic-theory/kinetic-theory—result-question-24.md (a) $15 RT$

(b) $9 RT$

(c) $11 RT$

(d) $4 RT$

[2017]

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Answer:

Correct Answer: 24. (c)

Solution:

  1. (c) Internal energy of the system is given by $U=\frac{f}{2} nRT$ Degree of freedom

$F _{\text{diatomic }}=5$

$f _{\text{monoatomic }}=3$

and, number of moles

$n(O_2)=2$

$n(Ar)=4$

$U _{\text{total }}=\frac{5}{2}(2) RT+\frac{3}{2}(4) RT=11 RT$