Question

Name the constituent collected at the top of
fractionating column during refining of
petroleum and why it is collected at the top?​

Answer 1

Answer:

Refinery Gases are collected at the top of the fractionating column.

Explanation:

It is collected at the top because it is a much smaller molecule. Smaller molecules have lower boiling points and get further up the column before they condense. The hydrocarbons in the refinery gas fraction have very small masses and their boiling points are very low.

Hope I answered correctly.