Why does cacl2 melt ice

Mail Us harold peterschemical. Magnesium Chloride Calcium Chloride vs. Rock Salt. Which do you use? Calcium Chloride vs. Fast acting: Calcium chloride begins to dissolve immediately upon application to break the bond between pavement and ice. Low eutectic point: calcium chloride melts at much lower temperatures than salt. The Pros of using Calcium Chloride Calcium chloride is effective down to a temperature of degrees Fahrenheit and is some two to 13 times faster than other products.

Calcium Chloride can melt the water in lower concentrations meaning you will have to spread a lot less on to get rid of that same patch of ice. Not only do you use less of it, but Calcium Chloride does not negatively impact plant life as drastically as Sodium Chloride.

Sodium Chloride is one of the most caustic ice melts out there not only on plants, but on concrete as well. Holy Guacamole, rock salt is cheap. It is cheap, cheap, cheap. We are glad you asked. Yes, blending both together gives you some of the benefits of both!

Viewed 93k times. My question is: Calcium chloride is a salt used widely to melt ice on sidewalks and roads. Improve this question. Gaurang Tandon 8, 10 10 gold badges 55 55 silver badges bronze badges.

Someone Someone 1 1 gold badge 3 3 silver badges 10 10 bronze badges. If you have a book around, take a quick look again at freezing point depression or cryoscopic effect and compare it with the boiling point elevation or ebulioscopic effect. In particular, notice how the equations are very similar.

What does this similarity imply? Add a comment. Active Oldest Votes. Improve this answer. Charles 2 2 silver badges 9 9 bronze badges. One mole of CaCl2 weighs almost as much as two moles of NaCl. So even taking van't Hoff factor into account, CaCl2 should be less effective per kilogram.

It is the higher solubility that matters and makes it more effective, despite the above. For NaCl, this quantity is slightly positive, about 3. CaCl2 has a large, negative heat of solution, seemingly in the range of that of NaOH, thus releasing heat that contributes to melting.

All that heat vanishes instantly into the environment.