State Raoult's law, If `DeltaT` is the elevation in boiling point of a solvent and `m` is no. of moles of solute per kilogram of solvent. What is the relationship between `DeltaT` and `m`?

Explanation

(a) In solution of volatile liquids, the partial vapour pressure of each component is directily proportional to its mole fraction
`P_(A)propX_(A)`
`P_(A)=P_(A)X_(A)`
`P_(A)=` Partial vapour pressure of component `A`
`X_(A)=` Mole fraction of component `A` in solution.
`P_(A)=` Vapour pressure of pure component `A`.
(b) The difference in boiling point of solution `T_(b)` and pure solvent `T_(b)^(0)` is called elevation of boiling point which is directly proportional to number of moles of solute in a given amount of solvent.
`{:(DeltaT_(b) = T_(b) - T_(b)^(@),,,DeltaT_(b) propm),(m="Molality",,,DeltaT_(b) = K_(b)m):}`