At what temperature the rms velocity of helium molecules will be equal to that of hydrogen molecules at NTP ?
At what temperature the rms velocity of helium molecules will be equal to that of hydrogen molecules at NTP ?
A. 844 k
B. 64 k
C. `273^(@)c`
D. 273 k
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Correct Answer - C
The root mean square velocity , `v_" rms"sqrt((3RT)/(M))`
where , R is gas constant , T the absolute temperature ans M the molecular weight.
Given , `v_(He)=v_(H),T_(H)=273K`
`M_(H)=2,M_(He)=4`
`therefore" " (v_(H))/(v_(He))=sqrt((T_(H))/(T_(He))xx(M_(He))/(M_(H)))`
`1=sqrt((273)/(T_(He))xx(4)/(2))`
`rArr " " T_(He)=546K`
In `^.(@)C, T_(He)=(546-273)^(@)C=273^(@)C`
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