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 (ATP) from food. It is formed by the oxidation of succinate by the enzyme succinate dehydrogenase. Fumarate is then converted by the enzyme fumarase to malate. Human skin naturally produces fumaric acid when exposed to sunlight. Fumarate is also a product of the urea cycle. 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