Sublimation Process

Sublimation occurs when a substance's thermal energy is increased to the point where the intermolecular forces holding the solid together are overcome, causing the solid to transition directly into a gas. This process bypasses the liquid phase entirely.

Examples of Sublimation

One common example of sublimation is the process by which dry ice, which is solid carbon dioxide, transitions directly into carbon dioxide gas without melting into a liquid. Another example is the way in which mothballs slowly sublimate, releasing a gas that repels moths.

Applications of Sublimation

Sublimation has several practical applications. In the laboratory, it is used to purify substances by separating mixtures of solids based on differences in sublimation temperatures. In addition, sublimation is used in freeze-drying, a process in which water is removed from frozen food or other substances without melting the ice, preserving the food's structure and flavor.

Study Guide for Sublimation

1. Define sublimation and explain the process by which it occurs.
2. Give examples of substances that undergo sublimation.
3. Discuss the practical applications of sublimation in the laboratory and in everyday life.
4. Explain how sublimation is used in the process of freeze-drying.
5. Compare and contrast sublimation with the processes of evaporation and condensation.