The gas oil fraction of petroleum has the highest boiling point?

A. True

B. False

 

The correct option is A. True.

1. Petroleum and Its Fractions:
   • Petroleum (crude oil) is a mixture of many hydrocarbons.
   • When it is refined, it is separated into different fractions by the process of fractional distillation.
   • Each fraction has a different boiling point range.
2. Order of Fractions (from lowest to highest boiling point):
   • Petroleum gas – lowest boiling point, used as LPG.
   • Petrol (gasoline) – used in cars.
   • Kerosene – used in lamps and jet fuel.
   • Diesel oil – used in trucks, buses, and trains.
   • Lubricating oil – used in machinery.
   • Fuel oil – used in ships and industries.
   • Gas oil / Residual oil – the heaviest fraction with the highest boiling point.
3. Gas Oil Fraction:
   • Also known as residual oil or heavy oil.
   • It remains after lighter fractions have distilled off.
   • It has the highest boiling point, often above 350–400°C.
   • It is thick, dark, and sticky in nature.
4. Uses of Gas Oil:
   • Used in making lubricating oil, paraffin wax, asphalt, and bitumen.
   • Also used as fuel in some industrial furnaces.

• The boiling point of a petroleum fraction depends on the size of hydrocarbon molecules. Larger molecules need more heat to vaporize, so they have higher boiling points.
• That is why gas oil, which contains the largest hydrocarbon molecules, comes out last in fractional distillation.

Note: Hence, it is correct that the gas oil fraction of petroleum has the highest boiling point.