Freezing Point
The temperature at which a liquid becomes a solid, numerically identical to the melting point of the pure substance.
Formula / equation
ΔT_f = K_f × m
Unit
°C
In depth
Freezing releases the latent heat of fusion as the ordered lattice forms. Dissolved solutes always depress the freezing point, in proportion to their molal concentration, which is why salt melts ice and antifreeze protects a radiator. Supercooling can delay freezing well below the true value.
Examples in the real world
Salting roads lowers water's freezing point to around −9 °C; ethylene glycol protects car coolant to −37 °C.