Noble Metals

I've looked everywhere and i havent been able to find what i need. The questions are: 1) noble metals resist what compounds?, 2) Examples of Noble metals? and 3)will they dissolve, if so in what?

for number 1, i thought noble metals would resist everything except for a few exceptions, but i looked up gold (which is a noble metal, i think) and it combines to form combounds a lot...another problem i had was while looking for examples of noble metals online i found two different answers one was Ag, Cu, and Au are noble metals another site says that metals like Pt, Ru and some others are noble metals. HELP ME I'M CONFUSED!! :cry:

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I think there are only 3 or 4 noble metals. Au, Ag and Pt are noble metals ( I`m sure ), and Cu is not. About their compounds: they get into reactions very hard, so there are only a few of their compounds ( AgCl for example ). For more, search this site.

Ft.......
Let me introduce myself first...my name is Ramos and come from China ....in a occational chance I find this forum maybe fit me so much...'coz my major is applicative chemistry and biotechnology....a grade 1 university student in Sun yet-sen university.

Ok come to this topic.(first time to discuss questions from the abroad ppl....really curious feeling....)

Noble metal(In china it is called 贵金属 "Gui jin shu"),"Gui" means noble,rare....And "jin shu" means metal.... So the "Noble metal" means a really rare but NOT get in to reaction very hard.There are really many metal can be called noble metal ....like Au,Ag,Pt(most frequently meet in our live) and some really scarce metal like Be, And some of the heavy metal like Ru,Rh,Pa,Os,Ir,Ni etc. can be also called "Noble metal"

And the reaction..maybe most of the noble metal is not activity....that's true....it's 'coz it's atomic structure is hard to break....but it's compounds is really exist....Like HAuCl4 ,AgCl, HPtF6 etc......And a principle must be make clear that is NO any relation between "Noble metal" and "Hard to get into reactions"...."Noble" here don't means cool,You certainly can understand wut I mean ,right? Hehe.

I think Chem would be correct on this question although you have good points Ramos

Hehe....maybe I don't understand the word "noble" means.....Or perhaps this principle is different between China and Western.But I CONFIRM my conclusion.

Noble metals

Noble metals are a hangover from alchemy; they resist oxidation or corrosion in the atmosphere. Before the advent of high NO2 and SO2 concentrations in the air; the base metals like Fe and Pb were attacked by the components of ordinary air. Pb forms a carbonate and will crumble away (there was a famous lead ring with a runic inscription in the British Museum whose reading can no longer be confirmed because the ring is now a heap of lead carbonate)

The original noble metals were those metals known to ancients which did not readily oxidize in a flame, namely, Ag, Au, and (believe it or not) Hg. Both Ag and Hg are readily attacked by nitric acid while gold is attacked only by free chlorine in an aqueous solution. Usually this is aqua regia, HNO3 and HCl; however, in a classic lecture hall demonstration, Au foil is unaffected in an atmosphere of anhydrous Cl, but the addition of a few ml of H2O causes the Au foil to disintegrate. The resistance of these three metals to oxidation was traditionally exploited as the technique of purification. The refiners fire (mentioned in Handel's Messiah) refers to the process in which the alloy was burned slowly in the fire; the base metals oxidized and were removed leaving the noble metal behind. In the case of Ag, the metal was actually prepared by burning galena, lead sulfide, until all the lead was converted to lead oxide, litharge, and a small bead of Ag remained. This process is called cupellation. With Hg, the technique is much the same but much more careful heating is required and its is not the dross that flakes away by the liquid that runs away (or floats away when the Hg vaporizes; condensation of the vapor is also required).

After the discovery of the New World, platinum was added to the list along with Ir, Os, Rh, Ru, and Pd. In point of fact, the inertness of these metals is a function of the primitive chemistry of ancient societies. Actually, Pt (and its relatives except for Os) form a thin oxide layer that (just like Al) prevents further reactions. The ready exchange of O2 with these metals is what makes them valuable catalysts. Os is slightly different, because its oxide is toxic and volatile. Or to put it another way, pieces of osmium stink and because the OsO4 so produced keeps floating away, the reaction continues, but like all of the noble metals at an remarkable slow rate. As has long been known, Pt labware requires special handling; a smoky flame with destroy a platinum crucible by creating a carbide which then decomposes leaving crystaline Pt which has no tensile strength. Au and Ag are soluble in sodium or potassium cyanide solutions; the platinum metals will dissolve in molten alkalies. Nevertheless, the relative inertness of these metals remains a fact of life and they retain the term noble.

interesting

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