The mass of one litre sample of ozonised oxygen at `NTP` was found to be `1.5 g`. When `100 mL` of this mixture at `NTP` were treated with terpentine oil, the volume was reduced to `90 mL`. Hence calculate the molecular mass of ozone.
(Terpentine oil absorbs ozone)

Explanation

As ozone is absorbed by turpentine oil, therefore, volume of ozone in 100mL of the mixture
`=100-90=10mL`
`therefore" "O_(2)" in the mixture"=100-10=90mL`
As 1 L of the mixture weigh = 1.5 g, therefore, average molar mass of the mixture (mass of 22.4 L at S.T.P.)`=1.5xx22.4=33.6"g mol"^(-1)`
`"Ratio of ozone " : "oxygen in the mixture "=10:90`
It m is the molecular mass of ozone, then
`"Average mol. mass of mixture "=(10xxm+90xx32)/(100)="33.6 (calculated above)"`
`"or "m+288=336 " or "m=48`