Freezing-point depression
Freezing-point depression is a drop in the maximum temperature at which a substance freezes, caused when a smaller amount of another, non-volatile substance is added. Examples include adding salt into water, alcohol in water, ethylene or propylene glycol in water, adding copper to molten silver, or the mixing of two solids such as impurities into a finely powdered drug.
Workers spreading salt from a salt truck for deicing the road
Freezing point depression is responsible for keeping ice cream soft below 0°C.
Pre-treating roads with salt relies on the warmer road surface to initially melt the snow and make a solution; Pre-treatment of bridges (which are colder than roads) does not typically work.
Dissolved solutes prevent sap and other fluids in trees from freezing in winter.
Deicing is the process of removing snow, ice or frost from a surface. Anti-icing is the application of chemicals that not only deice but also remain on a surface and continue to delay the reformation of ice for a certain period of time, or prevent adhesion of ice to make mechanical removal easier.
An Aeroflot Airbus A330 being deiced at Sheremetyevo International Airport
Econ Salt Spreader
Ice build up in train brakes jeopardizes braking efficiency.
A U.S. C-37B VIP jet gets deiced before departing Alaska in January 2012
