Question

The root mean square speed of hydrogen molecule at 300 K is 1930m/s. Then the root mean square speed of oxygen molecules at 900K will be………..
A. `1930sqrt(3)m//s`
B. 836 m/s
C. 643 m/s
D. `(1930)/(sqrt(3))m//s`

Answer 1

Correct Answer - B
`(C_(2))/(C_(1))=sqrt((T_(2))/(T_(1))(M_(1))/(M_(2))`
`=sqrt((900)/(300)xx(2)/(32))=sqrt((3)/(16))`
`C_(2)=(sqrt(3))/(4)xxC_(1)`
`=(sqrt(3))/(4)xx1930`
=836 m/s.