Q.What is the difference between simple distillation and fractional distillation?

Step 1. What each separates. Simple distillation purifies a liquid from non-volatile impurities, or separates liquids whose boiling points differ widely; fractional distillation is used specifically when the boiling points of the liquids in the mixture are not appreciably different, so simple distillation cannot cleanly separate them.

Step 2. Apparatus. Simple distillation uses a plain assembly — flask, thermometer, side arm, condenser, receiver — with no fractionating column. Fractional distillation adds a fractionating column, fitted between the flask and the point the vapour exits toward the condenser. …

Compare the two techniques on what they separate, the apparatus used, and …

• Saying the two techniques are identical except for 'one extra part' without explaining WHY the fractionating column matters — it is the repeated vapour-liquid exchange it enables that is the real functional difference. …