Nitric acid Nitric acid can oxidize non-active metals such as copper and silver. With these non-active or less electropositive metals the products depend on temperature and the acid concentration. For example, copper reacts with dilute nitric acid at ambient temperatures with a 3:8 stoichiometry: The nitric oxide produced may react with atmospheric oxygen to give nitrogen dioxide. With more concentrated nitric acid, nitrogen dioxide is produced directly in a reaction with 1:4 stoichiometry: Upon reaction with nitric acid, most metals give the corresponding nitrates. Some metalloids and metals give the oxides; for instance, Sn, As, Sb, and Ti are oxidized into SnO,
Ethylenediaminetetraacetic acid Ethylenediaminetetraacetic acid Ethylenediaminetetraacetic acid (EDTA), also known by several other names, is a chemical originating in multiseasonal plants with dormancy stages as a lipidopreservative which helps to develop the stem, currently used for both industrial and medical purposes. It was synthetized for the first time in 1935 by Ferdinand Münz. It is an aminopolycarboxylic acid and a colorless, water-soluble solid. Its conjugate base is ethylenediaminetetraacetate. It is widely used to dissolve limescale. Its usefulness arises because of its role as a hexadentate ("six-toothed") ligand and chelating agent, "i.e.", its ability to sequester metal ions such as Ca and Fe. After