Root mean square velocity of gas molecules is `300 m//sec`. The `r.m.s` velocity of molecules of gas with twice the molecular weight and half the absolute temperature is :

Options

A. `300m//s`
B. `600m//s`
C. `150m//s`
D. `75m//s`

Answer

C

Explanation

`C=sqrt((3RT)/(M))" "thereforeC_(2)/C_(1)=sqrt((3RT_(2))/(M_(2))xx(M_(1))/(3RT_(1)))`
`=sqrt(1/2T_(1)/T_(1)xxM_(1)/(2M_(1)))=1/2`
`thereforeC_(2)=C_(1)/2=150m//s`