The snow melt of the snow-melting agent theory is that "chlorine salt" deicing salt is soluble in water (snow), its freezing point zero, such as NaCl deicing (main component of salt) dissolve in water freezing at-10 c, calcium chloride at-20 ℃, acetic acid up to-30 degrees Celsius. Salts dissolved need outside heat, there is one effect is to make salt water freezing point depression, so after the salt is dissolved in water it is difficult to form ice again. In addition, the deicing salt is soluble in water, the ion concentration in water, liquid vapor pressure of the water drop, but the ice solid vapor pressure does not change. To reach ice water mixture of vapor pressure of solid and liquid States, ice will melt.
This principle can also be used to explain the truth of salt water is not easy to freeze. We know that water is a unique substance, namely frozen density becomes small (generally solid density is greater than the density of the liquid) and, therefore, greater pressure, lower the melting point of ice. Often, wheel went over where the snow is often easier to melt it. On the snow-covered pavement sprinkled with snow-melting agent, then the vehicle rolled, causes the snow to melt more easily. Visible on the CSSA, sprinkled with snow-melting agent to snow removal.