Concept

Freezing Point Depression

Freezing point depression is the lowering of the temperature at which a liquid turns into a solid when a dissolved substance is present. The solute particles get in the way of the water molecules arranging themselves into the orderly crystal lattice that makes ice, so a colder environment is required before the solid can form.

The effect matters because it provides a simple, reliable way to control the freezing behavior of everyday materials. Adding salt to icy roads keeps them from refreezing too quickly, antifreeze solutions in car radiators allow engines to operate well below water’s normal freezing point, and food scientists use sugar or salt brines to preserve meats and vegetables by keeping them liquid at temperatures that would otherwise solidify pure water.

You will also find freezing point depression wherever living organisms need to survive sub‑zero conditions. Some insects and fish accumulate dissolved proteins or salts in their body fluids so that the fluid remains unfrozen, letting life continue even when external temperatures drop below zero degrees Celsius.

1 read touches this

The Battery That Survived −40°C Did It with Less Salt, Not More
"The concentrated electrolytes are expensive … And they still freeze. The salt buys a little room below zero, but only a little; somewhere around −20 °C the performance falls apart."