Question

Mark the correct sequence of the substances obtained during fractional distillation of petroleum in ascending order of their boiling points.
A. Petroleum gas, Kerosene Petrol, Diesel, Paraffin wax
B. Petrol, Petroleum, Kerosene, Light oil, Diesel
C. Petrol gas, Petrol, Kerosene, Diesel, Lubricating oil
D. Petroleum gas, Petrol, Lubricating oil, Diesel, Kerosene

Answer 1

We know that petroleum is a liquid that occurs naturally beneath the surface of Earth. It is termed as fossil fuel as it is produced from the decomposition of organic matter over millions of years ago. Fractional distillation method is used to separate different components of petroleum, such as, petrol, diesel, paraffin etc.

Complete step by step answer:
Now, let’s briefly discuss the fractional distillation process. In this process, a mixture consisting of different substances of different boiling point is heated in a fractional column. In this process, vapors from the boiling solution passed along a column. The temperature of the column decreases along the length and components possessing higher boiling point undergo condensation on the column and return back to solution and the component with lower boiling point passes through the column and is collected. So, the basis on which fractional distillation occurs is the difference of boiling point of the components.

Now, come to the question. We have to arrange the petroleum products obtained in the process of fractional distillation in ascending order.

The petroleum gas has the lowest boiling point of $20^\circ {\rm{C}}$, boiling point of petrol (used in car) is $70^\circ {\rm{C}}$, then the boiling point of kerosene is $180^\circ {\rm{C}}$, then the boiling point of diesel is $260^\circ {\rm{C}}$ and the boiling point of lubricating oil is $300^\circ {\rm{C}}$.

So, the ascending order arrangement of the petroleum products is,

Petrol gas< Petrol
So, the correct answer is Option C.

Note: There are two types of distillation, simple and fractional distillation. In simple distillation, liquids are purified by bringing them to their boiling point and then collecting and condensing back to liquid. This process is useful when small impurities present in the mixture or liquids to be separated have widely different boiling points.