Crude petroleum is converted to useful products by the process of?

Analysis

The question asks for the specific industrial process used to separate crude oil into its various useful components (such as petrol, kerosene, diesel, and bitumen).

Concept Explanation

Crude oil is a complex mixture of hydrocarbons with different boiling points. Because these components have different molecular sizes and weights, they vaporize and condense at different temperatures. To separate them, we use a technique called fractional distillation.

In this process:

1. The crude oil is heated in a furnace.
2. The vapors enter a tall fractionating column.
3. As the vapors rise, the temperature of the column decreases.
4. Components with higher boiling points condense near the bottom, while those with lower boiling points rise higher before condensing.
5. This allows for the collection of different "fractions" at different levels of the column.

Step-by-Step Solution

• Option A (Fractional crystallization): This is used to separate solid mixtures based on differences in solubility at different temperatures. It is not suitable for liquid crude oil.
• Option B (Fractional distillation): This is the standard industrial method for separating liquids that are miscible and have different boiling points, which perfectly describes the refining of crude oil.
• Option C (Filtration): This is used to separate an insoluble solid from a liquid. It cannot separate the various hydrocarbons found in crude oil.
• Option D (Chromatography): This is used to separate small amounts of mixtures based on their movement through a stationary phase. It is a laboratory technique for analysis, not an industrial method for refining large volumes of petroleum.

Conclusion

Since crude oil is a mixture of hydrocarbons with varying boiling points, fractional distillation is the correct industrial process used to refine it.

Exam Tip: Remember that "Fractional Distillation" is for liquids with different boiling points, while "Fractional Crystallization" is for solids with different solubilities. Don't mix them up!