Is there a difference in corrosiveness of Calcium Chloride vs Magnesium Chloride?

Question

One or the other is used for dust control on our gravel roads. Magnesium Chloride is much more expensive, but people say Calcium Chloride is more corrosive for the metal in cars. Is that right?

Answer 1

That is right. The Ca++ Cl- bond is more ionic and less covalent than the Mg++ Cl- bond. It would be interesting to know the state where you live, where MgCl2 is less expensive than CaCl2. I once knew a chemistry professor in Michigan who used lactose (milk sugar) for his research. He said (in all seriousness), "It's so cheap, we use it to salt the roads!"