Freezing Point - Properties of Solutions
The freezing point of a material is the temperature at which it changes from a liquid to a solid. A liquid freezes when its vapour pressue is equal to the vapour pressure of its solid. The freezing point of water is 0oC.
You can modulate the freezing point of water by dissolving a non-ionizing solute in it. For e.g. a mole of sodium chloride or calcium chloride could depress the freezing point of water by 3.72oC and 5.58oC.