Fractional Distillation
AQA A-Level Chemistry
3.3.2
Crude oil is a complex mixture of hydrocarbons that contains molecules with a wide range of sizes and properties. Building on our understanding of alkanes, we can now explore how fractional distillation separates crude oil into fractions with different boiling points and uses. This provides the starting point for understanding the use of alkanes as fuels and why longer chain hydrocarbons need to be cracked into smaller, more useful molecules.
In this topic you will:
- Explain why crude oil must be separated before it can be used.
- Describe how fractional distillation separates crude oil into useful fractions.
- Explain why hydrocarbons condense at different heights within a fractionating column.
- Describe the trends in the properties of crude oil fractions as hydrocarbon chain length increases.
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