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?

Options

A. `0.3655`
B. `36.55`
C. `41.34`
D. `40.16`

Answer

C

Explanation

`p^(@)=1.013"bar"=1atm("at boiling point")`
`w_("solvent")=100-2=98g`,
`"According to Raoult's law, "(p^(@)-p_(s))/(p^(@))=(w_("solute"))/(M_("soulte"))xx(M_("solvent"))/(w_("solvent"))`
`(1.013-1.004)/(1.013)=(2xx18)/(M_("solute")xx98):.M_("solute")=41.34g" "mol^(-1)`