Hydrazoic acid was originally prepared by the reaction of aqueous hydrazine with nitrous acid. Other oxidizing agents, such as hydrogen peroxide, nitrosyl chloride, trichloramine or nitric acid, can also be used. In its properties hydrazoic acid shows some analogy to the halogen acids, since it forms poorly soluble (in water) lead, silver and mercury(I) salts. The metallic salts all crystallize in the anhydrous form and decompose on heating, leaving a residue of the pure metal. It is a weak acid (p"K" = 4.75.) Its heavy metal salts are explosive and readily interact with the alkyl iodides. Azides of heavier alkali metals (excluding
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