Kinetic Theory Of Gases Question 138

Question: A gas mixture consists of molecules of type 1, 2 and 3, with molar masses $ m _{1}>m _{2}>m _{3}. $ $ V _{rms} $ and $ \overline{K} $ are the r.m.s. speed and average kinetic energy of the gases. Which of the following is true

Options:

A) $ {{( V _{rms} )} _{1}}<{{( V _{rms} )} _{2}}<{{( V _{rms} )} _{3}} $ and $ {{(\overline{K})} _{1}}={{(\overline{K})} _{2}}=({{\overline{K}} _{3}}) $

B) $ {{( V _{rms} )} _{1}}={{( V _{rms} )} _{2}}={{( V _{rms} )} _{3}} $ and $ {{(\overline{K})} _{1}}={{(\overline{K})} _{2}}>{{(\overline{K})} _{3}} $

C) $ {{( V _{rms} )} _{1}}>{{( V _{rms} )} _{2}}>{{( V _{rms} )} _{3}} $ and $ {{(\overline{K})} _{1}}<{{(\overline{K})} _{2}}>({{\overline{K}} _{3}}) $

D) $ {{( V _{rms} )} _{1}}>{{( V _{rms} )} _{2}}>{{( V _{rms} )} _{3}} $ and $ {{(\overline{K})} _{1}}<{{(\overline{K})} _{2}}<{{(\overline{K})} _{3}} $

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Answer:

Correct Answer: A

Solution:

[a] $ v _{rms}\frac{1}{\sqrt{M}}$

$\Rightarrow$

$(v _{rms})_1$ <

$(v _{rms})_2$<

$(v _{rms})_3 $

also in mixture temperature of each gas will be same, hence kinetic energy also remains same.