At what temperature will the r.m.s. velocity of oxygen be one and half times of its value at S.T.P. ?

Answer

20.47

Explanation

`C_(r.m.s) prop sqrt(T)`
`therefore (c_(r.m.s))_(1)/((c_(r.m.s))_(2)) = sqrt(T_(1)/T_(2))`
`therefore c_(1)/(c_(1)/2) = sqrt(273/T_(2))..... (T_(1) = 273 K)` at S.T.P
`therefore T_(2) = 273/4`
`T_(2) = 68.25 K = (68.25 - 273)^(@) C`
`therefore T_(2) = -204.75^(@)` C