So I'm trying to make oil paints from scratch just for my own amusement, using boiled linseed oil as the vehicle and a bit of chemistry to make the pigments, inc. copper(II) acetate for blue, an indeterminate mixture of iron(III) oxides and acetates for orange, etc.
Well, I seized upon the idea of trying to prepare nickel(II) chloride hexahydrate, not just because it's a brilliant green on its own, but also because - as I understand - it can be mixed with a stoichiometric excess of ammonia to form a deep bluish-violet ammine complex.
So I have a mason jar (can't afford anything borosilicate) that I put a couple nickel-plated countersunk finishing washers which I thought
were brass underneath and covered with ~32% HCl (MSDS)
; later I stumbled upon this blog post about making NiCl2
O, which was using more or less the same process I was except with US $0.05 coins (which I didn't know were part nickel), which turned out to be something like 20x more cost-effective than buying finishing washers, so I chucked a couple nickels in the mason jar too. I also started a second mason jar with more nickels and HCl.
Well, after leaving them to dissolve for about a week, the 1st jar (washers + coins) was a dull, dark green and had flecks of undissolved but solid metal floating in it, while the 2nd gar was a more vibrant green with no precipitate. After decanting liquid part of the 1st jar, careful not to get any of the flakes into the new jar, and leaving it uncovered overnight to start evaporating, it turned... nearly black, with a slight amber tinge. This makes me suspect the metal underneath the nickel plating on the washers was iron (oxidized from Fe+2
overnight) all along, not brass, especially since the washers dissolved entirely and the coins (75% copper, 25% nickel, but no iron) didn't.
And that's where we are now.
The black-amber liquid from the 1st jar is still apparently acidic enough to react with aluminum, so I can't put it in an aluminum foil pan to speed up the evaporation process like the copper acetate or rust from before (plus it fumes slightly). The blog post from before instructed to boil the remaining liquid off, but I don't think my non-borosilicate mason jars could tolerate that kind of heat (one broke before over direct flame); I have a propane camp stove and stainless steel pot to decant them into, but after seeing what the solution did to the foil pan... I'm hesitant, not least of which because I want less
iron in solution, not more
- Can the 1st jar be salvaged, i.e. by removing the iron? (Precipitating it out with oxalic acid as iron(III) oxalate, perhaps?)
- If the problem with the 1st jar wasn't iron to begin with, how can I avoid ruining the 2nd solution and turning it the wrong color as well?
- What method is most likely to produce good green crystals without destroying my equipment or killing me?
(Safety and equipment notes: I'm doing all of this outside, which is about as "well-ventilated" as you can get without a fume hood, and on concrete instead of directly next to vegetation or anything flammable. I wear a dust mask and chemical-resistant gloves and goggles when handling the solutions, but I have essentially no other laboratory equipment whatsoever and, as mentioned before, use mason jars because I have no borosilicate beakers. All my raw materials are consumer-grade, by which I mean they're of low enough concentration and volume that you can get them at most hardware stores.)
Last note: since I'm new to the forums, I'm not sure if this is the right board or it should've gone in Undergraduate (which I am, but ChemE major instead of Chem, and this isn't homework or anything) or Inorganic. I'll probably also cross-post this to a couple other forums besides Chemical Forums since I'm not sure how active this place is.