Question

In the refining of petroleum, in a fractionating column, the principle use is_____
A. Difference in melting points
B. Difference in boiling points
C. Difference in freezing points
D. Difference in densities

Answer 1

Hint: We have to know the word petroleum is obtained from Latin words. Petro means rock and oleum means oil. We can say petroleum is a naturally occurring fluid that is taken out from the surface of the earth. In our day to day life we can use it as a source for several fuels.

Complete step by step answer: 

We know that petroleum is a mixture of hydrocarbons and it is formed by compression of organic matter. Over a million year ago, fossil fuel was formed by degradation of many organisms and compounds. Therefore, it is derived as dark coloured liquid oil from the rocks. It is otherwise called rock oil or black gold.
By fractional distillation method, we can separate the petroleum components. Distillation is boiling and then condensing. We use a fractionating column for separating the components of petroleum.
We know that a mixture of different types of hydrocarbons in large numbers is Petroleum. Alkanes (paraffin), cycloalkanes (naphthalenes), asphaltenes, aromatic hydrocarbons like benzene are some chemicals present in hydrocarbons. By fractional distillation method we can separate these chemicals. Based on the boiling point, we can separate the products (fuel oil, wax, petroleum gas, lubricating oil) from petroleum in which the compounds that have low boiling point are separated first. LPG, petrol, kerosene are the important constituents of petroleum.
In the refining of petroleum, in a fractionating column, the principle use is the difference in boiling points.
Therefore, option (B) is correct.

Note:
We have to know that LPG or liquefied petroleum gas is also called auto gas. LPG comprises propane, butane, propylene, and butylene in different mixtures. In the refining process of natural gas and petroleum LPG is produced as a by-product. In LPG, at normal temperatures and pressure, the components of propane and butane are present in equal percentages.