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. 300 m/sec
B. 600 m/sec
C. 75 m/sec
D. 150 m/sec

Answer

D

Explanation

`u = sqrt((3RT)/(M)) " or " (u_(1))/(u_(2)) = sqrt((T_(1))/(M_(1)). (M_(2))/(T_(2)))`
`:. (300)/(u_(2)) = sqrt((T)/(M) xx (2M)/(T//2)) " or " u_(2) = 150 ms^(-1)`