The root mean square velocity of the molecules in a sample of helium is `5//7th` that of the molecules in a sample of hydrogen. If the temperature of hydrogen sample is `0^(@)C`, then the temperature of the helium sample is about

Options

A. `0^(@)C`
B. 0 K
C. `273^(@)C`
D. `100^(@)C`

Answer

A

Explanation

`v_(rms)= sqrt((3RT)/(M)) rArrv_(rms) prop sqrt((T)/(M))`
`(v_(He))/(V_(H_(2)))=5/7sqrt((T_(He))/(M_(He))xx(M_(H_(2)))/(T_(H_(2))))rArrT_(He)=25/49xx4/2xx273~~0^(@)C`