Palladium, the least noble of the platinum group metals, already dissolves in plain HNO3, giving mixed Pd(II) and Pd(IV) species.
Repeatedly evaporating the resulting nitrate salt with HCl results in PdCl2 since Pd(IV) is a strong enough oxidiser to oxidise HCl to Cl2 at 100°C.
So all you really need is some of the metal.
[Edited on 9-7-2008 by garage chemist] |