In the bottom-to-top order of fractions, which is directly above bitumen?

In the bottom-to-top order of fractions, which is directly above bitumen?

• A. Heavy fuel oil
• B. Lubricating oil
• C. Diesel
• D. Kerosine

Answer: (A)

In fractional distillation, components are arranged by boiling point from bottom to top: heavier, higher-boiling fractions stay lower, while lighter, lower-boiling ones rise higher. Bitumen is the heaviest residue that remains at the bottom, so the next fraction above it must have a lower boiling point but still be quite heavy. That is heavy fuel oil, which sits directly above bitumen in the bottom-to-top order. Lighter fractions—lubricating oil, diesel, kerosene, and so on—continue above it as you move up the column.

In fractional distillation, components are arranged by boiling point from bottom to top: heavier, higher-boiling fractions stay lower, while lighter, lower-boiling ones rise higher. Bitumen is the heaviest residue that remains at the bottom, so the next fraction above it must have a lower boiling point but still be quite heavy. That is heavy fuel oil, which sits directly above bitumen in the bottom-to-top order. Lighter fractions—lubricating oil, diesel, kerosene, and so on—continue above it as you move up the column.