Sublimation

Sublimation refers to the process in which a substance transitions directly from its solid state to its gaseous state without passing through the liquid state. This occurs when the vapor pressure of the solid exceeds its melting point at a specific temperature and pressure.

Key Points:

• Phase Transition: Sublimation is a phase transition process where a substance transforms from a solid to a gas.
• Solid to Gas: Unlike conventional processes like melting and evaporation, sublimation skips the liquid phase.
• Temperature and Pressure: Sublimation occurs when the vapor pressure of the solid compounds exceeds its melting point at a specific temperature and pressure.
• Endothermic Process: Sublimation is an endothermic process, meaning it requires energy input to overcome the intermolecular forces and break the solid structure.
• Examples: Dry ice (solid carbon dioxide) sublimes at normal atmospheric pressure, while mothballs made of naphthalene also undergo sublimation.

Additional Information:

Sublimation has various applications in different fields. Some common uses include:

• Printing: In the field of printing, sublimation is used to transfer dye onto materials such as fabric or ceramics.
• Chemistry: Sublimation is utilized in the purification and separation of compounds via techniques like sublimation distillation.
• Freeze-Drying: The process of freeze-drying involves sublimating frozen water directly from ice to vapor, preserving the food or pharmaceutical product without major damage.

Overall, sublimation is a unique and interesting phenomenon that allows substances to transition from solid to gas without an intermediate liquid state.