What is Salt and How Does it Work?
Salt is a general term that refers to several types of chemical compounds. For example, sodium chloride (NaCl), calcium chloride (CaCl2), magnesium chloride (MgCl2), and potassium chloride (KCl) are all salts. The most common salt used on roads, sidewalks, steps, and driveways is sodium chloride which is also known as rock salt or road salt.
Salt Lowers the Freezing Point of Water
Water freezes into ice at 32°F. Salt applied to ice disrupts or breaks apart the ice structure by lowering its freezing point. This means that ice can melt at a lower temperature. Therefore, adding salt to ice causes it to melt. Different deicers lower the freeze point to different temperatures. Rock salt works well down to about 15°F. Magnesium and Calcium chlorides will work in colder temperatures. The colder the temperature, the slower the melting occurs and the amount of salt required increases.