Three vessels of equal capacity have gases at the same temperature and pressure. The first vessel contains…
Three vessels of equal capacity have gases at the same temperature and pressure. The first vessel contains helium (monoatomic), the second contains fluorine (diatomic) and the third contains sulfur hexafluoride (polyatomic). The correct statement, among the following is:
All vessels contain unequal number of respective molecules
The root mean square speed of molecules is same in all three cases
The root mean square speed of helium is the largest
The root mean square speed of sulfur hexafluoride is the largest
Solution
As, $\mathrm{V}_{\mathrm{rms}}=\sqrt{\frac{3 \mathrm{KT}}{\mathrm{m}}}$
Hence, $\quad v_{\mathrm{rms}} \propto \frac{1}{\mathrm{~m}}$
So, lower the mass, higher/greater the velocity. (where, the symbols have their usual meanings)