The pressure difference is given as, ∆p=23.8−23.324=0.476mm‌ of ‌Hg The expression for dilute solution is given as, ‌
∆p
p∘
=‌
wB
MB
×‌
MA
wA
Here, the molecular weight and actual weight of the solvent is MA and wA and the molecular weight and actual weight of the solute is MB and wB Substitute the value in above expression we get, ‌