The mass of a litre of oxygen at standard conditions of temperature and presssure is 1.43 g and the mass of one litre of `SO_(2)` is 2.857 g.
(i) How many molecules of each gas are there in this volume?
(ii) What is the mass in grams of a single molecules of each gas ?
(iii) What are the molecular masses of `SO_(2)` and `O_(2)` respectively?

Answer

(i) `2.688xx10^(22)` moles (ii) `O_(2)=5.320xx10^(-23)` g and `SO_(2)=10.629xx10^(-23)g`
(iii) `O_(2)=32.032u` and `SO_(2)=63.997u`

Explanation

`1LO_(2)orSO_(2)=(1)/(22.4)mol=(1)/(22.4)xx6.02xx10^(23)" molecules"=2.688xx10^(22)" molecules"`
`"Mass of 1 molecule of "O_(2)=(1.43)/(2.688xx10^(2))=1.0629xx10^(-23)g`
Gram Molecular mass of `O_(2)="Mass of 22.4 L at STP"=1.43xx22.4=32.032g`
`"Molecular mass of "O_(2)=32.032u`
Similarly, molecular mass of `SO_(2)` can be calculated.