Explain why an organic liquid vaporizes at a temperature below its boiling point during steam distillation.

(N/A) In steam distillation,steam is passed through the organic liquid. The mixture of water vapor and organic liquid vapor exerts a total vapor pressure equal to the atmospheric pressure $(P_{total} = P_{water} + P_{organic} = P_{atm})$. Since the total pressure is the sum of the partial pressures of water and the organic liquid,the organic liquid reaches its boiling point at a temperature lower than its normal boiling point (where its individual vapor pressure would equal $1 \ atm$).