Sublimation

Definition

Sublimation is the phase transition in which a substance changes directly from a solid to a gas without passing through the liquid state. This process occurs under specific conditions of temperature and pressure.

5 Must Know Facts For Your Next Test

1. Sublimation occurs when the pressure and temperature are below a substance's triple point in its phase diagram.
2. Common examples of sublimation include dry ice (solid CO2) turning into carbon dioxide gas and iodine crystals becoming iodine vapor.
3. The energy required for sublimation is known as the latent heat of sublimation.
4. Sublimation is an endothermic process, meaning it absorbs heat from its surroundings.
5. In chemistry laboratories, sublimation can be used as a purification method for certain compounds.

Review Questions

• What is the process called when a solid changes directly into a gas?
• Name two common substances that undergo sublimation.
• Explain why sublimation is considered an endothermic process.

Related terms

Deposition:

The phase transition in which a gas changes directly into a solid without passing through the liquid state.

Triple Point:

The unique set of conditions at which all three phases (solid, liquid, and gas) of a substance coexist in equilibrium.

Latent Heat:

The amount of heat absorbed or released by a substance during a phase transition at constant temperature and pressure.