Molecular hydrogen at one atmosphere and helium at two atmosphere occupy volume `V` each at the same temperature. The rms velocity of hydrogen molecules is `x` times the rms velocity of helium molecules. What is the value of `x`?

Options

A. `1`
B. `2`
C. `sqrt(2)`
D. `sqrt(3)`

Answer

C

Explanation

`C_(H_2) = xC_(He)`
As, `c prop 1/(sqrt(M))`
`sqrt(M_(He)) = xsqrt(M_(H_2))`
`sqrt(4) = xsqrt(2)`
or `x = (2)/(sqrt(2)) or x = sqrt(2)`.