Question 421: Thermodynamics & KTG

Question

A mixture of 2 moles of helium gas (atomic mass = 4 u), and 1 mole of argon gas (atomic mass = 40 u) is kept at 300 K in a container. The ratio of their rms speeds $\left[ {{{{V_{rms}}\,(helium)} \over {{V_{rms}}\,(\arg on)}}} \right],$ is close to :

Accepted Answer

We know,
V
rms
= $\sqrt {{{3RT} \over M}} $
Where M = molar mass of  the gas.
Here temperature is 300 K for both the gas. So  temperature is constant. R is also a constant.
$ 	herefore $   V
rms
$ \propto \,\,\sqrt {{1 \over M}} $
$ 	herefore $    ${{{V_{rms}}(helium|)} \over {{V_{rms}}\left( {\arg an)} ight)}} = \sqrt {{{{M_{Ar}}} \over {{M_{He}}}}} $
= $\sqrt {{{40} \over 4}} $
= $\sqrt {10} $
= 3.16

Answer

3.16

Answer

0.32

Answer

0.45

Answer

2.24

Thermodynamics & KTG

A mixture of 2 moles of helium gas (atomic mass = 4 u), and 1 mole of argon gas (atomic mass = 40 u) is kept at 300 K in a container. The ratio of their rms speeds \left[ {{{{V_{rms}}\,(helium)} \over {{V_{rms}}\,(\arg on)}}} \right], is close to :

Choose the correct answer: