Final answer:
Using two identical fractional columns stacked on top of each other in the distillation process can significantly increase the efficiency of separating methanol and water.
Step-by-step explanation:
Using two identical fractional columns stacked on top of each other in the distillation process can significantly increase the efficiency of separating methanol and water. The fractional distillation process separates substances based on their boiling points, with the lower boiling point substances condensing at the top of the column and the higher boiling point substances condensing at the bottom. By using two columns, the separation process is repeated, allowing for more precise separation and enhanced efficiency.