Easy MCQ +4 / -1 PYQ · JEE Mains 2021

The rms speeds of the molecules of Hydrogen, Oxygen and Carbon dioxide at the same temperature are VH, VO and VC respectively then :

  1. A V<sub>H</sub> &gt; V<sub>O</sub> &gt; V<sub>C</sub> Correct answer
  2. B V<sub>C</sub> &gt; V<sub>O</sub> &gt; V<sub>H</sub>
  3. C V<sub>H</sub> = V<sub>O</sub> &gt; V<sub>C</sub>
  4. D V<sub>H</sub> = V<sub>O</sub> = V<sub>C</sub>

Solution

${V_{RMS}} = \sqrt {{{3RT} \over {{M_W}}}}$<br><br>At the same temperature ${V_{RMS}} \propto {1 \over {\sqrt {{M_W}} }}$<br><br>$\Rightarrow$ V<sub>H</sub> &gt; V<sub>O</sub> &gt; V<sub>C</sub><br><br>Option (a)

About this question

Subject: Physics · Chapter: Thermodynamics · Topic: Zeroth and First Law

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