Physical Property Chemistry Example 4

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Example 4

hard
Ethanol has a boiling point of 78.4°C78.4°\text{C} and water boils at 100°C100°\text{C}. Explain how this difference in physical properties can be used to separate a mixture of ethanol and water.

Solution

  1. 1
    Since ethanol has a lower boiling point than water, heating the mixture will cause ethanol to vaporize first.
  2. 2
    The technique of distillation uses this difference: heat the mixture, collect the ethanol vapor, and condense it back to liquid in a separate container.
  3. 3
    The remaining liquid is enriched in water, while the collected distillate is enriched in ethanol.

Answer

Distillation separates them based on different boiling points.\text{Distillation separates them based on different boiling points.}
Distillation exploits differences in boiling points (a physical property) to separate miscible liquids. This is a fundamental separation technique used in chemistry, the petroleum industry, and beverage production.

About Physical Property

A characteristic of matter that can be observed or measured without changing the substance's chemical identity, including properties such as color, density, melting point, boiling.

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