पेट्रोल कैसे बनता है? | How Petrol is Extracted From Crude Oil | Doubtnut | Amba Ma'am

In this section, each item consists of six sentences of a passage. The first and the sixth sentences are given in the beginning as S1 and S6. The middle four sentences in each have been jumbled up and labelled P, Q, R and S. You are required to find the proper sequence of the four sentences S1: Crude oil obtained from the field is taken to a refinery for treatment. S6: Lubricating oils of various grades are obtained last of all P: The gas that comes off later is condensed into paraffin. Q : This allows substances with different boiling points to be separated. R : The first vapours to rise when cooled provide the finest petrol. S: The commonest form of treatment is heating. The proper sequence should be: