Nitric acid fuming nitric acid at concentrations above 86%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agent. Commercially available nitric acid is an azeotrope with water at a concentration of 68% HNO, which is the ordinary concentrated nitric acid of commerce. This
Fumaric acid Fumaric acid Fumaric acid or "trans"-butenedioic acid is the chemical compound with the formula HOCCH=CHCOH. Fumaric acid has a fruit-like taste and has been used as a food acidulant since 1946. Its E number is E297. It is produced in eukaryotic organisms from succinate in complex 2 of the electron transport chain via the enzyme succinate dehydrogenase. It is one of two isomeric unsaturated dicarboxylic acids, the other being maleic acid. In fumaric acid the carboxylic acid groups are "trans" ("E") and in maleic acid they are "cis" ("Z"). The salts and esters are known as fumarates. Fumarate can also