Question

Give reason why it is incorrect to write a chemical formula for petroleum?

Answer 1

Hint : Petroleum is the yellow-black liquid present in the earth’s rocks in a crude form, which can be extracted and refined to produce different varieties of oils including petrol, diesel oil, paraffin and oil.

Complete Step By Step Answer:
To answer this question, we have to understand the composition of the petroleum. So, basically petroleum is the mixture of hydrocarbons formed from the decomposition of the organic matter present beneath the surface of the earth over several years.
Thus, petroleum is the mixture of hydrocarbons and these hydrocarbons vary from $4$ to $12$ carbon atoms per molecule as ${C_4} - {C_{12}}$ . So, it is going to be a mixture of hexanes, pentanes and somewhat heptanes.
Generally, we would like to represent the petroleum by the general formula ${C_6}{H_{14}}$ i.e alkane and it going to consist the mixture of the isomers - $n -$ hexane, methyl pentane, and methylbutane and dimethylbutane.
So, from our above discussion we can conclude that it is incorrect to write the chemical formula for petroleum because of the fact that it is composed of a number of isomers.

Note :
There are some common types of petroleums available and they are – fossil fuel, gasoline, natural gas, kerosene, fuel, petrol. One interesting name is given to petroleum and it is “Black Gold”. Petroleum is known as black gold because it is used in the manufacturing of a variety of products including in the pharmaceutical sector, plastic, synthetic fibre and gasoline.