Nitric acid gold purity. Being a powerful oxidizing agent, nitric acid reacts violently with many non-metallic compounds, and the reactions may be explosive. Depending on the acid concentration, temperature and the reducing agent involved, the end products can be variable. Reaction takes place with all metals except the noble metals series and certain alloys. As a general rule, oxidizing reactions occur primarily with the concentrated acid, favoring the formation of nitrogen dioxide (NO). However, the powerful oxidizing properties of nitric acid are thermodynamic in nature, but sometimes its oxidation reactions are rather kinetically non-favored. The presence of small amounts of nitrous acid
Thiosulfurous acid They are immiscible in water, but dissolve in benzene or carbon tetrachloride. These species are less rigid than the thiosulfite esters. Thiosulfurous acid Thiosulfurous acid (HS−S(=O)−OH) is a low oxidation state (+1) sulfur acid. It is the equivalent acid for disulfur monoxide. Thiosulfurous acid is formed by reacting hydrogen sulfide and sulfur dioxide at room temperature. The thiosulfurous acid molecule is unstable when condensed, reacting with itself. It decomposes to polysulfane oxide or polythionic acids in water which is termed Wakenroder's liquid. Other possible isomers are dihydroxydisulfane or hypodithionous acid HOSSOH, a linear chain, and thiothionyl hydroxide (S=S(OH)) a tautomer