F

Freezing Point

ΔT_f = K_f × m; K_f(H₂O) = 1.86°C·kg/mol
Quick Reference
Formula / NotationΔT_f = K_f × m; K_f(H₂O) = 1.86°C·kg/mol
Also Known AsSolidification point, freezing temperature, melting point (same temperature), T_f

What is Freezing Point?

The temperature at which a liquid changes to a solid at a given pressure. For water under standard conditions, the freezing point is 0°C. The freezing point of a solution is lower than that of the pure solvent (freezing point depression), a colligative property.

Formula & Notation

ΔT_f = K_f × m; K_f(H₂O) = 1.86°C·kg/mol

Other Names / Synonyms: Solidification point, freezing temperature, melting point (same temperature), T_f

Properties & Characteristics

The freezing point is the temperature at which a liquid converts to a solid (solidification) at a given pressure, equal to the melting point of the solid. The normal freezing point is defined at 1 atm. Freezing point depression (ΔT_f = K_f × m, a colligative property) describes how dissolved solutes lower the freezing point; for water, K_f = 1.86°C·kg/mol. This is the basis of anti-freeze solutions.

Uses & Applications

Freezing point data is used in: designing antifreeze solutions for automotive and aircraft de-icing (ethylene glycol, propylene glycol), cryoscopy for molar mass determination, food freezing and preservation, cryopreservation of biological samples (with cryoprotectants), and pharmaceutical freeze-drying.

Safety Information

Antifreeze solutions (ethylene glycol) are acutely toxic if ingested (causes metabolic acidosis and renal failure from oxalate formation). Salt-based road de-icers lower freezing points but cause corrosion of metal infrastructure and environmental impacts on vegetation and aquatic ecosystems.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Freezing Point
Formula ΔT_f = K_f × m; K_f(H₂O) = 1.86°C·kg/mol
Synonyms Solidification point, freezing temperature, melting point (same temperature), T_f

Frequently Asked Questions

The temperature at which a liquid changes to a solid at a given pressure. For water under standard conditions, the freezing point is 0°C. The freezing point of a solution is lower than that of the pure solvent (freezing point depression), a colligative property.

More "F" Terms

View all "F" terms →
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z