The average translational energy and the rms speed of molecules in a sample of oxygen gas at `300K` are `6.21xx10^(-21)J` and `484m//s`, respectively. The corresponding values at `600K` are nearly (assuming ideal gas behaviour)

Options

A. `12.42 xx 10^(-21) J , 968 ms^(-1)`
B. `8.78 xx 10^(-21) J , 684 ms^(-1)`
C. `6.21 xx 10^(-21) J , 968 ms^(-1)`
D. `12.42 xx 10^(-21) J , 684 ms^(-1)`

Answer

D

Explanation

As average translational energy `prop` temp.
`:.` av. Translational energy becomes twice
i.e., rms speed `C prop sqrt(T)`
`:. C = sqrt(2) xx 484 ms^(-1) = 684 ms^(-1)`.