[Makubesu]

I was doing some research for a lab, and I found that AlCl3 apart from being really corrosive can actuall cause an explosion when in contact with water (http://en.wikipedia.org/wiki/Aluminum_chloride under hazards).  I did a little more searching on the net, and found that they usually store it as a hexahydrate to stop it from begin so dangerous.  I don't really understand why this works though, could someone explain the concept to me?

[Demotivator]

Because the hydrate water is like like kryptonite, sapping the bond energy of the Al-Cl bond through dipole interactions making them weaker, weaker, ...

[Makubesu]

Right, but why is it different when you put the AlCl3•6H20 in water than when you just put in AlCl3?  Is it just that less energy is released at once?

[Borek]

The problem is Al3+ cation desperately wants to be hydrated. It is small and highly charged. If you put it into water it will get hydrated pretty fast and a lot of heat will be released (hydration heat so to speak). This will immediately set water boiling. If you dissolve hexahydrate some solution heat will be released, but much less.

[Makubesu]

Okay, I understand it now.  Thanks!