Abstract Nitric acid solutions (c Pd up to 3.2 M) with variable HNO 3 concentration were studied by electronic spectroscopy, 14 N and 17 O NMR, acid-base titration, gravimetry, and other methods. Solid phases that precipitated on storing these solutions were studied by X- ray phase analysis, thermogravimetry, and IR spectroscopy. The conditions for stability of particular Pd (II) species were determined, and specific features of aging of such highly ...
