Chemistoftheelements

Congratulations to elementcollector1 on an outstanding effort into element producing and collecting. Even I don’t have the patience to try out all the above. We really need to hear more of this kind of thing, as I suspect there are a lot more of us that you’d think from searches on the internet. Theo Gray was one of my heros, but unfortunately, his websites don’t seem to have been updated for a long time: http://www.theodoregray.com/PeriodicTable/index.html http://www.periodictable.com/ To anyone who's interested, if you read these websites carefully, there are quite a few mentions of sources of the elements. Sorry if these have been mentioned before, but I've only just joined this forum. One caveat, though. I have stuck to the surviving primordial elements- I don’t mess with anything more radioactive than uraninite, which is the most radioactive natural substance you can encounter on earth. In the event of an accident, your body isn’t meant to deal with the sort of dose of radiation may encounter from the likes of the Am in smoke detectors. If you inhale a partice , it may sit there in your lung for a long time doing untold harm. Sorry to seem a bit alarmist, but anything outside the 83 primordials is a step too far.

I agree with elementcollector1 and insane_alien. The offficial line is that selenium is a very toxic element, and this is true. However, dire warnings about this element (as frequently encountered on the web and elsewhere) often fail to take into account the form and allotrope of the element. The element in the form of large chunks of grey i.e. “metallic” selenium which are free of fine particles of selenium, is not going to harm you so long as you don’t make a habit of hadling it, and wash your hands afterwards.

The Al foil in sodium hydrogen carbonate/NaCl solution method works because there is an appreciable difference in electronegativity between silver and aluminium, and when you place them in contact in a solution containing an electrolite, aluminium will function as an anode and corrode; meanwhile, hydrogen is building up on the cathode, which in this case is silver, which, probably being in its nascent form, reduces the AgS to Ag, and H2S is produced. As for the ammonia method, I don’t think this can be completely written off, as from an experiment I just did using 99.99% pure silver and 9% ammonia solution, there may be some sort of reaction, as the tarnished silver seemed to become became untarnished in places, although I should have taken pictures before and after to be sure, and until I can find some more decently tarnished silver I reserve judgement. HOWEVER, I just treated some very tarnished sterling silver with 9% ammonia solution for just a few seconds, and this proved a very effective means of removing tarnish. As for the influence of solubility of a substance on it’s ability to form a soluble complex, there are some extremely insoluble substances which form soluble complexes very easily- just dunk some titanium, zirconium or hafnium dioxides in HF to confirm this, or indeed the pure metals. The solubility of the substance you were trying to dissolve would, however, certainly influence the RATE of dissolution. HOWEVER, a while ago I tried dissolving some CuO as formed on a copper wire by heating in said ammonia solution, and the result was no detectable dissolution, while I know that Cu2+ while in solution, when neutralised with ammonia remains in solution as a soluble complex. Just some observations to throw into the discussion!

Elementcollector1, This is an interesting but difficult task you’ve set for yourself. From your previous experiments, during which you obtained a purple solution after dissolving your magnet, I suspect that the reason you had a purple solution was that you started with an alloy which consisted of cobalt and neodymium, at least in the main part. Many of the salts of both these elements are purple. The dark green ingredient to which you allude is likely iron (probably a mixture of FeII and FeIII) rather than Praseodymium, as the latter is, from my experience, definitely light green, although you could possibly have praseodymium in there as well as iron. As for separation using the diffential solubilities of Fe and Nd hydroxides, I’m afraid that’s impractical, as they’re both extremely insoluble and the quantities you’d likely get would be so small as to make recovery very difficult if not impossibe for the amateur chemist using the resources we have available to us. I looked into producing some simple representitive compounds of neodymium and praseodymium a while back, as I’m a keen element collector and amateur metallurgist, and decided that the chlorides would be way to hygroscopic to be useful. I settled on sulphates/ sulfates, and succeeded in producing some decent crystals stable in humidities of at least 90%. To produce large crystals (~ 1mm)relatively free of basic sulfate, ie Nd/Pr(OH)SO4, however, you need to begin with more metal than will dissolve in the H2SO4 and remain in solution; in other words, you have to exceed the solubility of (Nd/Pr)2(SO4)3 in sulfuric acid, wait intil you have a decent amount of crystals but still have a very acidic solution, then decant off the solution, leaving the crystals, which you will have to dry by tissue paper. You will then need to neutralise any acid you have on your tissue and anywhere else, of course. In the case of neodymium, if you rely on evaporation from a solution of weak acid, then your precipitate will turn orange, because you have produced Nd(OH)SO4. I started with Neodymium and Praseodymium metals, and I know you’re actually aiming to end up with what I started with, but some of the things I learned may be of use to you. You have almost certainly encountered some of the compounds I did, but for different reasons. Turning these into Nd metal will be very difficult, though, and you may have to settle with a representitive compound. All this needs to be done, of course, with gloves, specs and other protective equipment, an outdoors if you’re going to do any heating, and always have plenty of sodium bicarbonate on hand to soak up and neutralise any acid spills.