Question

What does crude oil consist of? What does fractional distillation do to crude oil?

Answer 1

We know that crude oil is a raw material that is extracted from the ground. It generally consists of various hydrocarbons. Fractional distillation is used to separate these different hydrocarbons from crude oil.

Complete answer:
Crude oil is a mixture of various hydrocarbons which exist in liquid state in natural underground reservoirs. They remain in liquid form even when brought to the surface. Oil is generally referred to as petroleum. But petroleum includes crude oil, condensate and gas. Crude oil can be extracted from the ground using a drilling process. Then it is further refined into fuels like kerosene, petrol, diesel and some heavy waxes. Some petroleum plants use the process called cracking to reduce the size of large molecules of hydrocarbons. The components in crude oil have different boiling points. So, fractional distillation is used to separate the substances present in crude oil. The crude oil is evaporated and then the vapors are condensed at different temperatures in the fractionating column. Each fraction contains hydrocarbons having the same number of carbon atoms.

Note:
Remember that the hydrocarbons having high molecular weight will have stronger dispersion forces which increases the boiling point, making them less volatile in nature. They do not flow and ignite easily. The hydrocarbons having less molecular weight will have weaker dispersion forces which decreases the boiling point, making them very volatile in nature. They also flow and ignite easily.