Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In steam distillation, the organic liquid vaporises at a temperature lower than its normal boiling point. Reason (R): The organic liquid boils when the sum of its vapour pressure and the vapour pressure of water equals the atmospheric pressure. In the light of the above statements, choose the most

Step-by-step solution

Assertion (A) is correct. In steam distillation, the organic liquid vaporises at a lower temperature than its normal boiling point, which prevents its decomposition. Reason (R) is also correct and explains Assertion (A). During steam distillation, the mixture of the immiscible organic liquid and water boils when the sum of their vapour pressures equals the atmospheric pressure ( P_ total = p_ organic + p_ water = P_ atm ). Because the partial vapour pressure of the organic liquid ( p_ organic ) is less than the atm