# Solve this following

Question:

The rms speeds of the molecules of Hydrogen, Oxygen and Carbondioxide at the same temperature are $\mathrm{V}_{\mathrm{H}}, \mathrm{V}_{\mathrm{O}}$ and $\mathrm{V}_{\mathrm{C}}$ respectively then :

1. $\mathrm{V}_{\mathrm{H}}>\mathrm{V}_{\mathrm{O}}>\mathrm{V}_{\mathrm{C}}$

2. $\mathrm{V}_{\mathrm{C}}>\mathrm{V}_{\mathrm{O}}>\mathrm{V}_{\mathrm{H}}$

3. $\mathrm{V}_{\mathrm{H}}=\mathrm{V}_{\mathrm{O}}>\mathrm{V}_{\mathrm{C}}$

4. $V_{H}=V_{O}=V_{C}$

Correct Option: 1

Solution:

$\mathrm{V}_{\mathrm{RMS}}=\sqrt{\frac{3 \mathrm{RT}}{\mathrm{M}_{\mathrm{W}}}}$

At the same temperature $\mathrm{V}_{\mathrm{RMS}} \propto \frac{1}{\sqrt{\mathrm{M}_{\mathrm{w}}}}$

$\Rightarrow \mathrm{V}_{\mathrm{H}}>\mathrm{V}_{\mathrm{O}}>\mathrm{V}_{\mathrm{C}}$

Option (1)