Talk:Rhodium/Archive 1

Archive 1

biological activity and jewlery

The article says: "Compounds that contain rhodium are not often encountered by most people and should be considered to be highly toxic and carcinogenic. Rhodium compounds can stain human skin very strongly. This element plays no biological role in humans."

If that is really true, why is it used to plate jewlery? 71.199.123.24

-The article means COMPOUNDS, not the actual metal itself. the base metal is harmless but compounds such as rhodium (III) fluoride or rhodium (III) chloride

Borislav Dopudja 18:51, 2 July 2006 (UTC)

Elemetal rhodium is harmless, but his salts should be treated as a deadly poison.

Rhodium in 'Grills'

As many may know, Rhodium is used in plating jewelry. Among this jewelry, now commonly found to contain Rhodium, are Grills (dental jewelry most popular in hip hop fashion.)There has been talk of Rhodium making the wearers 'sick'; though no actual symptoms were specified. Perhaps more research should be done in this area.

Gold is also poisonous. [1] --Vuo 10:20, 16 July 2006 (UTC)

Gold may very well be toxic - the issue is that it's so inert that normally you're hard pushed to get any compounds formed in the first place. There are a handful that I've come across - lithium auride I think is one, along with LiAuCl and some others like the arthritis drug aurothioglucose. Oh. This is a discussion on Rhodium. Never mind. Dan Pope 00:42, 7 December 2006 (UTC)

Sources for Utah mining

According to the USGS, in their most recent platinum group mining summary, no Rhodium was mined in the United States -> [2]. Hipocrite - «Talk» 14:00, 26 May 2007 (UTC)

A source does not necessarily have current mining going on. Also, [3] says that US production is primarily platinum and palladium, but does not say entirely. --JWB 17:29, 26 May 2007 (UTC)

Well, certainly if someone can find a reliable source stating that there is substantial Rhodium in Utah, we could include it. Hipocrite - «Talk» 18:46, 26 May 2007 (UTC)

I have an unreliable source -- my bank account for WMG ventures since we take about 22 ounces a year of Rhodium out of there. There's also numerous reliable sources in the form of mining claims filed with the BLM office in SLC regarding platinum (Rhodium is a by product) mineral deposits in that area. Look for references of 1900's mining claims for "Gold Hill" in that area. Jeffrey Vernon Merkey 02:50, 28 May 2007 (UTC)

Furnace Winding

What is a furnace winding in this context? —Preceding unsigned comment added by 209.169.125.74 (talk) 07:10, 9 July 2008 (UTC)

Acid

One part of the article said it was not attacked by acids, and slightly attacked by aqua regia. Later in the article there was an uncited statement saying that sulfuric acid completely dissolves rhodium. Aqua regia is far stronger than pure sulphuric acid, and can completely dissolve metals that sulphuric acid cannot even attack. 24.65.95.239 (talk) 01:25, 1 December 2008 (UTC)

Recovery of Fission Rhodium

Can User:Cadmium please provide a source for the changes made regarding the radioactivity of fission rhodium? This article gives an activity of 1.3×10^-3 Ci/g after 5 years, which would be about 640 MBq for 13.3 grams, although this was apparently based on a different assumption about the half-life than the values given in Nubase. —Ta180 19:57, 14 June 2007 (UTC)

That article gives that figure per gram of ¹⁰²Rh, and says that isotope occurs only in trace quantities. --JWB 00:33, 15 June 2007 (UTC)

Well, yeah. Most fission products have a high number of neutrons and then undergo beta decay, but ¹⁰²Rh can not be formed in this way, as ¹⁰²Ru is stable. Formation of ¹⁰²Rh is an unlikely event, and as such only trace quantities are present. However this isotope and its nuclear isomer account for nearly all the radioactivity. The issue is that no sources were cited, and there's a 10x discrepency in these numbers.—Ta180 09:27, 15 June 2007 (UTC)

The point is that the article you cited gives a figure per gram of ¹⁰²Rh, and this Wikipedia article gives a figure for 13.3 grams of fission rhodium containing a small quantity of ¹⁰²Rh. It does not give any figure per gram of ¹⁰²Rh, though it can be computed. It states the initial proportion of ¹⁰²Rh in fission rhodium is 6.62×10⁻¹², and that the proportion surviving after 5 years is 4.7/67.1, or .464×10⁻¹² of fission rhodium, or 6.17×10⁻¹² gram per 13.3 grams. If the activity of this 6.17×10⁻¹² gram is 4.7 MBq, then the activity per gram is .762×10¹² MBq per gram.

Also, the article you cited gives a ratio of about 40 between the specific activities of ¹⁰²Rh and ^102mRh, while the ratio of halflives is 5 in the opposite direction. Does the decay energy really differ by a factor of 200?. --JWB 16:21, 15 June 2007 (UTC)

Becquerels and curies are units of decays per time, not decay energy. An activity of 1.3×10^-3 Ci/g for pure ¹⁰²Rh would correspond to a half-life of several million years, which makes no sense, so I assumed that this was referring to the total activity of the rhodium, and not just ¹⁰²Rh. I'm not arguing that the PMR paper is accurate, I am questioning the complete lack of sources in this article. —Ta180 01:11, 17 June 2007 (UTC)

In the "From Nuclear Fuels" section, it starts off talking about rhodium, but every other reference in the paragraph is to ruthenium. Is this a cut-and-paste error? Or is it somehow intentional? —Preceding unsigned comment added by 134.223.116.200 (talk) 23:49, 9 June 2010 (UTC)

Thanks! I changed it.--Stone (talk) 14:26, 10 June 2010 (UTC)

Talk

Added a comment about the sharp price decline of rhodium as a result of the global slowing economy.

is rhodium a conductor? —Preceding unsigned comment added by 89.105.2.254 (talk) 12:01, 15 January 2010 (UTC)

---

Rhenium

Rhenium is not a precious metal. Am deleting the comment about it being so. —Preceding unsigned comment added by 69.27.245.170 (talk) 16:56, 27 August 2008 (UTC)

Does Rhodium in Jewlery items pause any danger of radiation? many white gold items from india have Rhodium in it and I am not sure if they are safe Please reply

Are you sure about the specific heat? I think you may be off by a factor of 1000.

The Rhodium page talks about reactivity with oxygen at length, or rather the lack thereof. Then in the table entry about Oxidation State, it talks about an amphoteric oxide. I suspect there is some algorithm generating this entry, as there is no means of editing it (that I see). I would like to see the mention of an oxide dropped with respect to the oxidation states available for Rhodium. Fortran (talk) 23:35, 3 January 2008 (UTC)

I found a factual error in the article. In the article it states that only small amounts of rhodium will dissolve in aquaregia. But if you bring the aquaregia to boiling temp It will dissolve both platinum and rhodium. I do this on a regular basis. As this is my bussiness.[user 69slinkys] 8:50 24 feb 2008 —Preceding unsigned comment added by 209.247.21.245 (talk) 15:52, 24 February 2008 (UTC)

It appears the Young's modulus and Bulk modulus values had been interchanged earlier, which I have now corrected. Poisson's ratio nu=0.26, and Young's modulus E=380 GPa are consistent with ASM Metals Handbook. Bulk modulus K = E/{3(1-2*nu)} shows that K must be less than E if nu is less than 1/3. This relation would give K=263 GPa.

Two other citations of sources reported on the web give K=275 GPa at 293.15K: K=275 GPa Darling, A.S. Journal of the Institute of Metals. 1966. K=274.5862 GPa, J.R.Handley. JM Internal document.

I have not checked the primary reference for these last two sources, but this is enough support to indicate that the earlier values for K,E had been interchanged. This error also occurred in another standard websource www.webelements.com and I have written to the editors of that source as well. Rbbwiki (talk) 23:55, 7 April 2008 (UTC) Rbbwiki (talk) 23:58, 7 April 2008 (UTC)

Unusual Property

Rhodium supposedly will not react with Fluorine, even though it will form compounds with Oxygen, Chlorine, etc.

See Talk:Fluorine/Archive 1#Rhodium. Double sharp (talk) 10:19, 31 January 2012 (UTC)

Nuclear source

If significant amounts of rhodium occur in spent nuclear fuel, what is it a decay or fission product of? --Carnildo 05:27, 28 December 2005 (UTC)

According to the Chart of the Nuclides (14th Edition), the yield of mass number 103 from fission of U-235 is 3.03% from U-235, 1.57% from U-233, and 7.0% from Pu-239. Of course, Rh-103 is only 1 of many isotopes with a mass number of 103 which are produced. Rh-103 is the only stable isotope with a mass number of 103, so it will be the end product of beta minus decays from the neutron rich side and beta plus/electron capture decays from the neutron deficient side. Beta decay/electron capture is the only decay mechanism present, so all mass 103 produced by fission of U-233, U-235 or Pu-239 will result in Rh-103 eventually. The two longest lived isotopes at mass number 103 are Ru-103 (39.27d) on the neutron rich side and Pd-103 (16.99d) on the neutron deficient side. Fortran (talk) 23:30, 3 January 2008 (UTC)

File:Rhodium powder pressed melted.jpg to appear as POTD soon

Hello! This is a note to let the editors of this article know that File:Rhodium powder pressed melted.jpg will be appearing as picture of the day on July 27, 2012. You can view and edit the POTD blurb at Template:POTD/2012-07-27. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks! —howcheng {chat} 08:29, 25 July 2012 (UTC)

Picture of the day

Rhodium, one of the rarest metals on Earth, in three states of processing: one gram in powder form, a one-gram pressed cylinder, and a one-gram argon arc remelted pellet. Rhodium is a chemically inert precious transition metal found as a free metal or in platinum or nickel ores together with the other members of the platinum group metals.Photo: Alchemist-hp

record for getting closest to absolute zero?

If I remember correctly this was used to set the record in 1999 for getting closest to absolute zero (it got to 10^-10 K) - shouldn't this have a mention? 220.255.1.68 (talk) 12:18, 2 August 2011 (UTC)

You're right, see Absolute_zero#Very_low_temperatures. I'll try to work it into the article. Tomásdearg92 (talk) 17:50, 22 December 2012 (UTC)

Monsanto process?

Why is there no mention of the importance of Rh in the Monsanto process?http://en.wikipedia.org/wiki/Monsanto_process#section_1 — Preceding unsigned comment added by 129.130.18.100 (talk) 18:08, 13 February 2013 (UTC)

Rhodium#Catalyst. --Makecat 06:10, 14 February 2013 (UTC)

Conflict, dissolved by Aqua regia or not?

"Diluted nitric acid dissolved all but palladium and rhodium, which were dissolved in aqua regia" - History section in this article. "However, aqua regia does not dissolve or corrode titanium, iridium, ruthenium, rhenium, tantalum, niobium, hafnium, osmium, or rhodium"- Following link from Aqua regia article.

Tumorte (talk) 07:51, 7 August 2016 (UTC)Tumorte. 2016-08-07. 09:51.

Good point. Greenwood and Earnshaw (p. 1116) write "Rhodium and iridium...are especially notable for their extreme inertness to acids, even aqua regia. Dissolution of rhodium metal is best effected by fusion with NaHSO₄, a process used in its commercial separation." Double sharp (talk) 11:00, 7 August 2016 (UTC)

+1 I know it from my own experiments too. I clean always Rh (and Ir) shavings with aqua regia with no Rh losses (or "only" µg amounts). --Alchemist-hp (talk) 13:24, 7 August 2016 (UTC) P.S: take a look above to the POTD ;-)

Furthermore, Greenwood and Earnshaw also give the actual account of the history. "In 1803 both rhodium and iridium were discovered, like their preceding neighbours in the periodic table, ruthenium and osmium, in the black residue left after crude platinum had been dissolved in aqua regia. W. H. Wollaston discovered rhodium, naming it after the Greek word ῥὀδον for "rose" because of the rose-colour commonly found in aqueous solutions of its salts." I'll make the necessary changes. Double sharp (talk) 14:16, 7 August 2016 (UTC)

Thanks for the changes. Rh and Ir are better soluble in a mixture of NaClO₃ + conc. HCl. Ru + Os in a solution of LiClO. --Alchemist-hp (talk) 17:25, 7 August 2016 (UTC)

Use of Rhodium for electrical contact plating?

There is no mention of rhodium's electrical conduction properties, nor is there mention of electrical components (ie power recepticals, contacts, etc) plated with rhodium (and the theoretical performance improvement, if any, resulting from this). — Preceding unsigned comment added by 198.2.107.38 (talk) 04:09, 17 January 2019 (UTC)

potato concentration

The reference paper https://www.mdpi.com/2304-8158/8/2/59 abstract says:

The quantification limits for Pt and Rh are 0.007 and 0.0008 μg kg−1 respectively. Considering all the potato samples, concentrations of Pt and Rh vary in the ranges from 0.007 to 109 μg kg−1 (sample no, 6 potatoes grown in Sicily) and from 0.0008 to 0.030 μg kg−1 (sample no. 3 of potatoes grown in Emilia Romagna), respectively.

I think this means that Rhodium appears in potatoes in a concentration between from 0.0008 to 0.030 μg kg−1.

1 μg kg−1 would be 1 part per billion (ppb) or 1e-9, 0.001 μg kg−1 would be 1 part per trillion (1e-12), so 0.0008 means 0.8 parts per trillion (ppt) or 8e-13, and 0.030 μg kg−1 means 30 ppt.

So we need to correct this sentence: "Rhodium is present in potatoes in a range between 109 ppb to 7 ppt" (which already sounds unlikely, which is why I'm here :) - it appears that a previous editor has confused the Platinum and Rhodium concentrations.

I suggest: "Rhodium has been measured in some potatoes in concentrations between 0.8 and 30 ppt".

Hagrid67 (talk) 16:04, 18 January 2020 (UTC)

Grammatical Error

Where?

The sentence that first mentions the Median Lethal dosage thing on rats in the Precautions section has a grammatical error.

What?

It states, " Median lethal dose (LD50) for rats is 198 mg of rhodium chloride (RhCl3) per kilogram of body weight. "

How?

To Fix

It should be, "The median lethal dose (LD50) for rats is 198 mg of rhodium chloride (RhCl3) per kilogram of body weight."

Corrected by

• Decapitalizing "Median"
• Adding "The"

Please edit, as I have given a detailed description on how to edit and where to edit. --Thingy9 (talk) 01:54, 20 March 2020 (UTC)Thingy9

Thank you for this analysis; I made the correction. In the future, though, you can be bold and fix it yourself! ComplexRational (talk) 01:57, 20 March 2020 (UTC)