Why is crude oil separated into fractions?

Why is crude oil separated into fractions?

• A. To remove impurities
• B. To make them more useful
• C. To increase viscosity
• D. To reduce boiling point

Answer: (B)

Crude oil is a mixture of many hydrocarbons with a wide range of boiling points. By heating it in a fractional distillation column, components with lower boiling points vaporize first and rise higher, while heavier ones stay liquid until higher temperatures. As the vapors cool at different levels, they condense into separate fractions, each containing hydrocarbons with similar boiling points. The purpose of this separation is to make the products more useful, since each fraction can be used for specific applications like petrol, kerosene, diesel, or lubricating oils, and can be refined further as needed. It’s not mainly about removing impurities, increasing viscosity, or reducing the crude’s overall boiling point—the separation is about producing useful fractions with appropriate properties.

Crude oil is a mixture of many hydrocarbons with a wide range of boiling points. By heating it in a fractional distillation column, components with lower boiling points vaporize first and rise higher, while heavier ones stay liquid until higher temperatures. As the vapors cool at different levels, they condense into separate fractions, each containing hydrocarbons with similar boiling points. The purpose of this separation is to make the products more useful, since each fraction can be used for specific applications like petrol, kerosene, diesel, or lubricating oils, and can be refined further as needed. It’s not mainly about removing impurities, increasing viscosity, or reducing the crude’s overall boiling point—the separation is about producing useful fractions with appropriate properties.