170135_inorganicventures_flipping

11:2 Acid Diges-ons of Inorganic Samples

Nitric Acid Diges-ons: Summary of some common inorganic dissolu-ons

§ Dilute 10 - 15 % aqueous dilution - Alkaline earth oxides, lanthanide oxides, actinide oxides, Sc 2 O 3 , Y 2 O 3 , La 2 O 3 . § 1:1 HNO 3 + H 2 O - V 2 O 5 , Mn oxides, Cu, Cd, Hg oxides Tl oxides, Pb oxides, Bi oxides, Cu, Zn, Cd, Hg, Pb. Concentrated (69%) HNO 3 - Mn, Fe (hot), C, A, Pd (hot), Se, As, Bi, Re. § 1:3 HNO 3 + HCl – Pt, Au, steel, Fe/Ni alloys, Cu alloys, Cr/Ni steel. § 1:1:1 HNO 3 + HF + H 2 O - The metal and oxides of Ti, Zr, Hf, Nb, W, Sn, Al, Si, Ge, Sb, Te, As, Se, Mo and numerous alloys and ox ide mixtures containing one or more of these elements.

11:3 Acid Diges-ons of Inorganic Samples

Nitric Acid Diges-ons:

In the examples listed above nitric acid is ac4ng as a strong acid where inorganic oxides are brought into solu4on... (1) CaO + 2H 3 O + ⇔ Ca +2 + 3H 2 O and as an oxidizing agent / acid combo where zero valence inorganic metals and nonmetals are oxidized and brought into solu4on... (2) Fe o + 3H 3 O + + 3HNO 3 (conc.) ⇔ Fe +3 + 3NO 2 ↑(brown) + 6H 2 O (3) 3Cu o + 6H 3 O + + 2HNO 3 (dilute) ⇔ 2NO↑ (clear) + 3Cu +2 + 10H 2 O In addi4on, nitric acid does not form any insoluble compounds with the metals and non- metals listed. The same cannot be said for sulfuric, hydrochloric, hydrofluoric, phosphoric, or perchloric acids.