An HCl molecule has rotational, translational and vibrational motions. If the rms velocity of HCl molecules in its gaseous phase is `vec(v), m` is its mass and `k_(s)` is Bolzmann constant, then its temperature will be `(mv^(2))/(nk_(B))` , where n is __________ .

Options

A. `(mv^(2))/(6k_(B))`
B. `(mv^(2))/(3k_(B))`
C. `(mv^(2))/(7k_(B))`
D. `(mv^(2))/(5k_(B))`

Answer

a

Explanation

In this case the total degree of freedom is 6.
According to law of equipartition of energy,
`(1)/(2)mv^(2)= 6((1)/(2)k_(B)T)`
`(1)/(2)mv^(2)= 3k_(B)T`
or `T= (mv^(2))/(6k_(B))`