Making Nickel (II) chloride hexahydrate

2009-03-09 22:58 by Ian

Here I will detail a process for making technical grade nickel (II) chloride hexahydrate from household chemicals.

You will need: (at minimum)

A US nickel is 25% nickel metal and 75% copper. At a mass of 5g, each US nickel contains 1.25g of nickel metal. Hydrochloric acid doesn’t attack copper under normal circumstances. We can therefore use HCl to leech nickel from the alloy. This will cause nickel to enter its preferred oxidation state of 2+ and bind to the free chlorine ions in solution, liberating hydrogen gas in the process…
2HCl + Ni + 6H2O -> NiCl2•6H2O + H2

Salts of nickel, like many other metal’s salts, have a strong affinity for polar ligands. In this case, that ligand is water. But it may also be ammonia, or an alcohol. Immediately after the formation of the salt, water molecules will collect around the metal ion as the chlorine atoms pull electrons away from it, thereby inducing a partial positive charge on the nickel.

The result will be a green salt that should look like this:

Nickel (II) chloride hexahydrate


Some pictures:
Here is a closeup of the nickels. You can see where I’ve drilled the nickels, and all the metal shavings that resulted. This reaction has been running for about four days. The color representation is accurate.

Nickels in acid, macro view.

Most of the large turnings have fallen apart into smaller pieces as metal is leeched from them. Here is a view of the most granular material left in the jar. If you look closely, you can just make out the distinctly copper hue as the nickel is leeched, leaving the copper component of the alloy in place.
Metal shavings in the jar.

Now that you have your fancy salt, put a small sample of it in a flame and observe the striking color.
You can now use this salt to do various things. You can pass a current through its aqueous solution and extract the high-purity nickel metal. It is also a weak Lewis acid. Without knowing the purity, it would be ill-suited for a chemical reagent. But knowing the purity isn’t too difficult. Maybe I’ll go into it later.

What did I do with it? I dissolved it in anhydrous denatured alcohol and threw it in a spray bottle so I could blow bright blue fireballs.

This is almost certainly not safe. But isn’t that part of what makes it so awesome?