Gold with hydrofluoric, hydrochloric, hydrobromic, hydriodic, sulfuric, or nitric acid. It does react with selenic acid, and is dissolved by aqua regia, a 1:3 mixture of nitric acid and hydrochloric acid. Nitric acid oxidizes the metal to +3 ions, but only in minute amounts, typically undetectable in the pure acid because of the chemical equilibrium of the reaction. However, the ions are removed from the equilibrium by hydrochloric acid, forming AuCl ions, or chloroauric acid, thereby enabling further oxidation. Gold is similarly unaffected by most bases. It does not react with aqueous, solid, or molten sodium or potassium hydroxide. It does
Acid–base reaction chemistry. The ECW model is quantitative model that describes and predicts the strength of Lewis acid base interactions, −Δ"H". The model assigned "E" and "C" parameters to many Lewis acids and bases. Each acid is characterized by an "E" and a "C". Each base is likewise characterized by its own "E" and "C". The "E" and "C" parameters refer, respectively, to the electrostatic and covalent contributions to the strength of the bonds that the acid and base will form. The equation is The "W" term represents a constant energy contribution for acid–base reaction such as the cleavage of a dimeric