Sublimation of Dry Ice
Direct Phase Change from Solid to Gas
Observe how dry ice (solid CO₂) sublimates directly into gas without passing through the liquid phase. Watch the particles transition from a solid crystalline structure to freely moving gas molecules!
Solid CO₂ (Dry Ice)
Temperature: ❄ -78.5°C (Sublimation Point)
Observation:
Dry ice maintains its solid form at -78.5°C. The particles are locked in a crystalline structure with minimal vibration.
The Science Behind Sublimation
Key Concepts:
Sublimation is the direct transition from solid to gas without passing through the liquid phase:
- Dry Ice: Solid carbon dioxide (CO₂) at -78.5°C at standard pressure
- Sublimation Point: The temperature and pressure at which a solid turns directly into gas
- CO₂ Phase Diagram: At normal atmospheric pressure, CO₂ cannot exist as a liquid, only as solid or gas
Process Explanation:
When dry ice is exposed to higher temperatures, the CO₂ molecules gain enough energy to break free from the solid structure directly into the gas phase. This is different from melting where the substance would first become liquid.
