Melting ice with salt- what is the difference between Calcium, potassium and magnesium chlorides?

Question

The hardware store has many choices. What is the science behind it? Is one better than the other?

Answer 1

Calcium and magnesium chloride will produce 3 ions while KCl only produces 2 ions. The more ions, the lower the melting point of the ice, and so the more effective the icemelt stuff. You ultimately have to balance cost with effectiveness, I think. In theory, at least, one pound of either magnesium or calcium chloride will melt ice as well as 1.5 pounds of potassium chloride.

Answer 2

The problem is not so much which will work or work slightly better than another as much as what the salts will do to the environment after the snow and ice are gone.

This is one of the reasons why the rock salt (Sodium chloride) use is becoming less common.

Chlorides are not very friendly to plants. They also tend to harden the soil. You might want to consider using Calcium magnesium acetate (CMA) if you are just using a little around your home or office. It is expensive, but not as expensive as having to replant lawn or flowers due to chloride poisoning.

Urea is also good and is a fertilizer, not a toxic chemical in usual amounts.

Answer 3

u know whats cool, in the bar we use ice and salt to make the beer colder in the large tubs :)

ANd I always thought, salt helped melt ice on the roads