Sciencemadness Discussion Board - "platinum chloride"

"platinum chloride"

woelen - 2-7-2007 at 14:11

I recently purchased 8 ampoules of so-called "platinum chloride", and I think it is hexachloroplatinic acid, H2PtCl6.6H2O. Because of this, I already made the following webpage:

http://woelen.scheikunde.net/science/chem/compounds/chloropl...

I, however, still have some doubts on this. If I read MSDS's and other literature, then the color of the material I have seems somewhat too red.

What is the idea of other's over here? Is this really hexachloroplatinic acid, or is this some other compound of platinum?

I do not believe it is real platinum (II) chloride, because the latter is insoluble in water and not hygroscopic. The material in the ampoules looks quite deliquescent and it also looks as being very soluble in water.

garage chemist - 2-7-2007 at 14:14

That must have cost some serious money!

Yes, I'm sure it is hexachloroplatinic acid. The fact that the material is not individual crystals but rather pieces broken from a chunk speaks for this- look in Brauer, it says that the molten hexachloroplatinic acid is left to solidify in moulds.

olmpiad - 2-7-2007 at 14:15

That looks like hexachloroplatinic acid. I've made it myself, and its color is much like that!

woelen - 2-7-2007 at 14:26

Thanks for your quick responses. I paid EUR 50 for all 8 of these ampoules (shipping was included in the price). Indeed quite some money, but I think it was worth the cost.

For the time being I intend to break up one of these ampoules and use that for experiments, I intend to keep three or four of these for my collection of rare materials and the remaining ones I probably will use to make a platinum coated anode, but before I do that, I will first need to do more research on that subject.

The_Davster - 2-7-2007 at 14:31

Looks like the hexachloroplatinic acid I have used.

But I absolutly love those labels!

EDIT: WOW that is an awesome price!

[Edited on 2-7-2007 by The_Davster]

garage chemist - 2-7-2007 at 14:40

50€ is absolutely unbelievably cheap for that!
The platinum in those 8 grams is worth far, far more!
The seller must have been very stupid. A reasonable price for those 8 grams would be 200€.

I once requested the price for one gram of hexachloroplatinic acid from a chemical company, it was something around 80€.

Nerro - 2-7-2007 at 15:23

In other words, make a gram of Pt from it and make your money back. From there on you can be wasteful with it all you want without feeling guilty

G.i.B. - 2-7-2007 at 18:06

It is good to see you made a good purchase woelen, I had my doubts when I first saw those vials. In retrospect I should have taken them myself..... After taking of the labels, they look a lot better.

Platinum prices are at a record high of 50 dollar/gram and there are three grams in those vials. Nice......

DerAlte - 2-7-2007 at 20:59

Pretty sure you’re right, Woelen. Back around 1953 my father made a chem. Lab at our home and equipped it with wonderful amounts of chemicals and apparatus. Among these were small stoppered vials of a gold salt (hydrochloroauric acid) and a platinum salt labeled as hydrochloroplatinic acid (from BDH in UK). . Memory, a bit strained over that many years, says they were both yellow. They were both deliquescent. We dissolved them to make a ?N solution.

Not sure what the gold salt was useful for, but the Pt salt was a reagent to test for potassium; the K salt is “sparingly soluble” (as are the ammonium, caesium, rubidium; the Na salt quite soluble). Father was an enthusiast for qualitative analysis.

According the Mendeleev, Principles of Chem, 1897, the salt is, as you said, H2 Pt Cl6. 6H20, and the color is ‘reddish brown’ so my memory was wrong. The solution was yellow. Pauling, in General Chemistry, 1953, says the chloroplatinate ion, PtCl6- - is a coplanar octahedral covalent complex ion. I.e., the Pt is 4-valent. PtCl4 exists, apparently: the usual process is to use aqua regia, when the salt crystallizes out of acid solution as the chloroplatinic ion and is quite souble. PtCl2 is green and insoluble (all according to M, loc, cit.)

Regards,

DerAlte

woelen - 3-7-2007 at 04:38

Nice to read all. those confirmations. Tonight I'll edit the webpage, to make it sound more certain

. And indeed, EUR 50 for this material is a good price, but I did not know it is that expensive.

@G.i.B.: Buying this stuff indeed was a little gambling for me, hence I decided to let it go if the seller would ask more than EUR 50. I saw the picture of the material, and it did not look very good, but I hoped it would only be outside the ampoules. When I received the material, it even looked worse

. Loads of crap (black stuff and brown very sticky dirt) on the glass vials. I first let them soak in water for 4 hours, then I cleaned them with a mix of 30% HCl and some KBrO3 in it (makes mix of Br2 and Cl2), and finally I wiped them with a cloth, wetted with acetone. The black and brown stuff was really sticky and dirty, but fortunately, I could remove it. Unfortunately, most of the labels had to be sacrificed in this process of cleaning. I could save 3 of them, and even these three have bad spots and brown gunk on them. But the glass vials now are nice and clean again, the solid inside is nice and dry (no leaking of glass vials!) and that is most important

Fleaker - 3-7-2007 at 09:31

It is a good price. Based on it's platinum content of that salt, it should be worth about 91.50€, assuming they give you spot price, which they won't (more like 94% at the best). There's ~3.013g of platinum if this is what it looks to be. You would have better luck selling the salt to someone who does platinum plating (perhaps a jeweler who needs to replatinize one of his own electrodes) rather than a refiner. Should sell well with a label, and the fact it's in a sealed ampoule.

based on 31.104 g/troy ounce, 1 gram of platinum is 30.49€ at the moment compared to $41.56/g in the US. Spot price at http://www.kitco.com

Not quite as much as some hoped, but still a damn good deal considering what you got. I think it was the condition of those vials that might have lowered the price.

Nice find!

DerAlte - 3-7-2007 at 13:31

If you will pardon me, an anecdote, not too far OT. (Rosco Bodine has had a gentle dig at me elsewhere for ancient yarns; I feel he is either coeval with me or a historian as well as his other talents!)

When I was at school I was a bright young bugger, always top in one of the science subjects, Math, Applied Math, Physics or Chemistry. When in the 6th form (=12th grade AP, US) we were asked to describe the reaction of platinum with aqua regia in a homework assignment. I had the Mendeleev book (loc. cit. above) and wrote that H2PtCl6 was the result. Damn it, we had a vial so labeled in our little lab.

It came back with a big X and an ominous “See me” written on it. The Chemistry master was excellent, demonstrated most things, and was very well liked by the class. Where had I screwed up?

“Mr X” he said (6th form boys were so addressed – masters were ‘Sir’ – we had strict formal discipline then), “Your answer was wrong. According to the context you have been taught, the answer should have been PtCl4. Yet you were right – a complex is formed, but we haven’t discussed complexes yet. That comes later.” He proceeded to give a mini-lecture on complexes in his office, and I actually took notes! It started an interest in complexes.

The moral of this is (1) The professor is always right. ( In later life, the boss; in academia, authority). (2) Don’t be a smart-ass. This lesson was as useful as the science.

Regards,

DerAlte

chemkid - 3-7-2007 at 13:42

Being right isn't smart ass

woelen - 3-7-2007 at 14:03

Quote:

Originally posted by Fleaker
It is a good price. Based on it's platinum content of that salt, it should be worth about 91.50€, assuming they give you spot price, which they won't (more like 94% at the best). There's ~3.013g of platinum if this is what it looks to be. You would have better luck selling the salt to someone who does platinum plating (perhaps a jeweler who needs to replatinize one of his own electrodes) rather than a refiner. Should sell well with a label, and the fact it's in a sealed ampoule.

Fortunately I feel no need to sell the material

. But it is good to read that I made a good deal. I have been looking on Internet and to my surprise one of the sellers from whom I purchased some chemicals now also sells precious metal salts:

Precious metal salts, price list

His price is $25 per gram, minimum purchase must be 5 grams for this acid. Still this seems quite good to me, especially, when compared to that price of EUR 80 per gram, mentioned by garage chemist.

[Edited on 3-7-07 by woelen]

garage chemist - 3-7-2007 at 14:36

Yeah, 25€ per gram is reasonable, my 200€ for 8 gram were actually guessed though.

From chemical suppliers, precious metal salts are often much overpriced, dont know why that is.

With precious metals, it is always best to buy the metal and make the salts of it yourself. Its really the cheapest way.

Sometimes though, this can be hard, for example with the metals that are impervious to all acids and aqueous dissolution agents in general. Like Ruthenium and Iridium powder. The standard way to get Iridium into solution is to mix with NaCl and heat it in a stream of chlorine in a pipe furnace.
For Ruthenium, its an oxidising melt of NaOH and NaNO3 in a silver crucible that has to be used.

Fleaker - 4-7-2007 at 08:23

That's $25 garage chemist, so even cheaper!

I seem to recall that one could oxidize iridium in a KOH+ KHSO4 melt and dissolve the resulting IrO2 residue in aqua regia. That could be one route, rather than work with the halogens.