Principles of Coldness

The Cooling Properties of Salt

Salt crystals are well known for their distinctive physical behavior when exposed to different temperatures. Unlike many other natural substances, salt gives a natural sensation of coolness to the touch, and this is closely related to its physical and chemical properties.

• Crystalline Structure:
  Salt is a crystalline compound that reflects and distributes heat differently from organic matter or metals, which gives it a naturally cool surface feel.

• Endothermic Dissolution:
  When salt dissolves in water, the process absorbs heat from the surrounding environment. This endothermic reaction makes the salt solution feel cooler than the ambient temperature.

• Lowering the Freezing Point:
  Salt has the ability to reduce the freezing point of water. When mixed with ice, the salt-ice mixture can reach temperatures as low as –21°C. This unique property has been used historically in food preservation and is still applied in various modern cooling processes.

• Industrial and Practical Use:
  Because of these thermal characteristics, salt has long been utilized in refrigeration methods, road de-icing, and even laboratory experiments to demonstrate thermal reactions in solutions.