freezing-point depression

physics

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 23, 2026

Quick Summary

Freezing-point depression is a phenomenon in physical chemistry where the freezing point of a liquid is lowered when a solute is dissolved in it. This effect depends on the concentration of the solute particles, not their specific identity.12

For example, adding one mole of a nonionic solute to 1,000 grams of water lowers the water's freezing point by 1.885 °C. This principle is utilized in applications like adding antifreeze to a car's radiator to prevent the cooling water from freezing. The process of a solid forming from a mixture can also change the liquid's composition, progressively lowering the freezing point.34

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

4 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

liquid
Decrease in freezing point
Another colligative property of solutions is the decrease in the freezing temperature of a solvent that is observed when a small amount of solute is dissolved in that solvent. By reasoning similar to that leading to equation (5), the freezing-point depression, ΔT_f,…
Read More
Another colligative property of solutions is the decrease in the freezing temperature of a solvent that is observed when a small amount of solute is dissolved in that solvent. By reasoning similar to that leading to equation (5), the freezing-point depression, ΔT_f,…
Read More

Why Does Salt Melt Ice?
This concept is called “freezing point depression.” Essentially, the salt makes it harder for the water molecules to bond together in their rigid structure. In water, salt is a solute, and it will break into its elements. So, if you’re using table salt, also known as sodium chloride (NaCl),…
Read More
This concept is called “freezing point depression.” Essentially, the salt makes it harder for the water molecules to bond together in their rigid structure. In water, salt is a solute, and it will break into its elements. So, if you’re using table salt, also known as sodium chloride (NaCl),…
Read More