Nitric acid concentrated acid and nitric oxide for dilute acid. or Concentrated nitric acid oxidizes I, P, and S into HIO, HPO, and HSO, respectively. Nitric acid reacts with proteins to form yellow nitrated products. This reaction is known as the xanthoproteic reaction. This test is carried out by adding concentrated nitric acid to the substance being tested, and then heating the mixture. If proteins that contain amino acids with aromatic rings are present, the mixture turns yellow. Upon adding a base such as ammonia, the color turns orange. These color changes are caused by nitrated aromatic rings in the protein. Xanthoproteic
Methanesulfonic acid Methanesulfonic acid Methanesulfonic acid (MsOH) is a colorless liquid with the chemical formula CHSOH. It is the simplest of the alkylsulfonic acids. Salts and esters of methanesulfonic acid are known as mesylates (or methanesulfonates, as in ethyl methanesulfonate). It is hygroscopic in its concentrated form. Methanesulfonic acid may be considered an intermediate compound between sulfuric acid (HSO), and methylsulfonylmethane ((CH)SO), effectively replacing an –OH group with a –CH group at each step. This pattern can extend no further in either direction without breaking down the –SO– group. Methanesulfonic acid can dissolve a wide range of metal salts, many of them