Question

NaCl or CaCl2 which is effective to melt ice? Why? Help please.

Answer 1

Let's figure out how many molecules are produced first.
we do this for both reactions:
we count up the total number of molecules produced to get the van hoff factor i

\[NaCl --> Na ^{+} + Cl ^{-}\] 2 molecules, so i = 2

\[CaCl_{2} --> Ca ^{+} + 2Cl ^{-} \] 3 molecules so i = 3.

I think that CaCl2 would be better/more effective to melt ice. @shalante thoughts?

Answer 2

You're referring to the van't hoff equation there.
Higher the ionice strength of the salt solution, the lower the melting point. CacL\(_2\) would be more effective than salt (NaCl)
CaCl\(_2\) which is highly soluble in water and a nice hygroscopic nature that attractss and holds water.

Answer 3

it's called the van't hoff factor, but both answers are correct

http://www.kentchemistry.com/links/Math/vant%20hoff.htm