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
Base metal is sometimes called 'base metal' or deprecated as 'muckite'. In the context of plated metal products, the base metal underlies the plating metal, as copper underlies silver in Sheffield plate. Base metal A base metal is a common and inexpensive metal, as opposed to a precious metal such as gold or silver. A long-time goal of alchemists was the transmutation of a base (low grade) metal into a precious metal. In numismatics, coins often derived their value from the precious metal content; however, base metals have been also used in coins in the past and today. In contrast to noble