Does fluoroantimonic acid dissolve noble metals? Nernst equation suggests that platinum would require pH ≈ −20.1 to be dissolved, using Hammett acidity function as an extension of pH scale it seems that it should dissolve in fluoroantimonic acid. On the other hand possiblility of dissolving gold depends on the exact value of acidity function as it would require pH ≈ −25.7 to be dissolved (fluoroantimonic is sometimes stated to have H0 = −31.3). However wikipedia says that Hammett acidity function of fluoroantimonic acid is in range: −21 > H0 > −23.
|Reaction||Standard electrode potential||"pH" required to dissolve|