Here's why:
* Freezing Point Depression: Adding a solute (like salt) to a solvent (like water) lowers the freezing point of the solution. This is a colligative property, meaning it depends on the concentration of the solute, not its identity.
* Disruption of Crystal Lattice: Salt dissolves in water, forming ions. These ions disrupt the regular crystal lattice structure of ice, making it harder for water molecules to form solid ice. This leads to a lower freezing point.
Practical Example: This is why salt is used to melt ice on roads and sidewalks in winter. The salt lowers the freezing point of water, preventing the ice from forming or melting existing ice.
