An aqueous solution of `2` per cent `(wt.//wt)` non-volatile solute exerts a pressure of `1.004` bar at the boiling point of the solvent. What is the molecular mass of the solute?

Explanation

`P^(@)A=1atm=1.013"bar", Ps =1.004"bar"`
`W_(B)=2g" "W_(s)=100g//mol " "W_(A)=98g`
`(P^(@)A-PS)/(P^(@)A)=X_(B)" "implies" "(P^(@)A-PA)/(P^(@)A)~(nB)/(nA)`
`(1.013-1.004)/(1.013)=(2)/(M_(B))xx18/98impliesM_(B)=(2xx18)/(98)xx(1.013)/(0.009)`
` thereforeM_(B)=41.35g//mol`