Question

Calculate the biling point of a solution containing 0.456 g of comphor (molar mass=152 g mol^(-1)) dossoved in 31.4 g of acetone(b.p.= 329.45 K). Given that the molecular elevation constant per 100 g of solvent is 17.2 K.

Answer 1

Calculation of elevaltion in boiling point `(T_(b))`.
`DeltaT_(b)=(K_(b)xxW_(B))/(M_(B)xxW_(A))`
Mass of camphor `(W_(B))=0456 g`
Mass of acetone `(W_(A))`=31.4 g= 0.0314 kg
`" Molal elevation contant "(K_(b))=(17.2K per 100 g)/1000=1.72 "K kg mol"^(-1)`
`" Molar mass of camphor "(M_(B))=152 g mol^(-1))`
`DeltaT_(b)=((1.72 K kg mol^(-1))xx(0.456 g))/((152 g mol^(-1))xx(0.0314 kg))=0.164 K`
Calculation of boiling point of solution.
Boiling point of acetone= 329.45 K
Elevation in b.p tempertaure=0.164 K
Boiling point of solution=329.45K+0.164 K= 329.614 K