Fuel

11. O/N 2013/P11/Q37

The diagram shows the fractionation of crude oil.

Which row explains why fraction R is collected above fraction S?

Answer: ​​ D

Explaination

Here fraction R is distilled at top of the fractionating column because fraction R ​​ has lower boiling point and having lower weight (smaller HC chain) whereas, fraction S is ​​ distilled at bottom of the fractionating​​ column because fraction S ​​ has higher boiling point and having higher weight (bigger HC chain).​​