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………..

Options

A. `1930sqrt3"ms"^(-1)`
B. `836"ms"^(-1)`
C. `643"ms"^(-1)`
D. `(1930)/sqrt(3)"ms"^(-1)`

Answer

B

Explanation

Using the relation, `3 =sqrt((3RT)/(M))`
`"Hence, " (c_(o_(2)))/(c_(H_(2)))=sqrt((T_(O_(2)))/(T_(o_(2)))xx(M_(H_(2)))/(M_(o_(2))))=sqrt((900)/(300)xx(2)/(32))=sqrt(3)/(4)`
`c_(o_(2))=sqrt(3)/(4)c_(H_(2))=sqrt(3)/(4)xx1930"ms^(-1)`
`=835.69~~836"ms"^(-1)`