Sublimation

Sublimation is a phase transition process in which a substance changes directly from a solid to a gas without passing through the liquid phase. This occurs when the substance's vapor pressure exceeds its atmospheric pressure at a certain temperature.

Examples of Sublimation

• Dry Ice (Solid Carbon Dioxide): When dry ice is exposed to room temperature, it sublimes directly from a solid to a gas, creating the characteristic fog or "smoke."
• Iodine Crystals: Solid iodine can sublimate when heated, producing a purple vapor.
• Camphor: Solid camphor can sublime at room temperature, releasing a strong, distinctive odor.

Sublimation in Nature

Sublimation is a common process in nature. For example, in cold, dry climates, snow and ice can sublimate directly into water vapor without melting first. This is known as "snow evaporation."

Study Guide

Here are some key points to remember about sublimation:

1. Sublimation is the process of a substance changing directly from a solid to a gas.
2. It occurs when the substance's vapor pressure exceeds its atmospheric pressure at a certain temperature.
3. Common examples of sublimation include dry ice (solid carbon dioxide) and solid iodine.
4. Sublimation is a natural process that occurs in various environmental conditions, such as cold, dry climates.
5. Sublimation can also be used in laboratory and industrial processes, such as freeze drying and purification of substances.