The following are bye-products of crude oil EXCEPT

Analyze the question: You are asked to pick the one item that is NOT obtained from crude oil. This is an "EXCEPT" question, so four options are petroleum products and one is not.

Concept: Crude oil is refined by fractional distillation, which separates it into products according to their boiling points. Common products include:

• Petroleum gases (LPG, cooking gas)
• Petrol (gasoline)
• Kerosene (paraffin oil)
• Diesel
• Lubricating oils
• Paraffin wax
• Bitumen (tar/asphalt), the heaviest residue

Check each option:

• A. Bitumen: the residue left after distillation, used for road construction. It is a crude oil product.
• B. Kerosene: a fraction used for lamps, stoves and jet fuel. It is a crude oil product.
• C. Paraffin wax: obtained from the heavier fractions, used for candles and polish. It is a crude oil product.
• D. Perfume: perfumes are made mainly from essential oils from flowers and plants, with alcohol and fixatives. Crude oil is not the main source, so it is not a typical by-product.
• E. Petrol: a major refined fraction. It is a crude oil product.

Tip: In "EXCEPT" questions, first identify the group (here, fractions from distilling crude oil), then eliminate the options you recognise. Remember the order of the fractions from lightest to heaviest: gas → petrol → kerosene → diesel → lubricating oil → wax → bitumen. Anything not on this list, like perfume, is the exception.