1. Fractionation columns are generally more efficient if they are insulated to maintain a gradual temperature gradient in the column. Why is there a temperature gradient in a fractionation column?

A. Higher up the column, the vapor becomes enriched with the low-boiling fraction and the boiling point of the liquid decreases.

B. Higher in the column, the vapor is enriched with the high-boiling fraction and the boiling point of the liquid decreases.

C. Higher in the column, the vapor is enriched with the low-boiling fraction and the boiling point of the liquid increases.

D. Higher in the column, the vapor is enriched with the high-boiling fraction and the boiling point of the liquid increases.

2. Why is it important that water enters from the bottom of the cooler and not the top? A. Water entering from the bottom keeps the cooler full of water. B. Water entering from the top is too heavy to handle. C. The bottom of the cooler needs to be cooler for the vapor to condense before collection.