Under what name was nitric acid known to alchemists?
Nitric acid Nitric acid Nitric acid (HNO), also known as aqua fortis (Latin for "strong water") and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% HNO, it is referred to as "fuming nitric acid". Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as white fuming nitric acid at concentrations above 95%, or red
Nitric acid nitric acid's boiling point of 83 °C. A nonvolatile residue of the metal hydrogen sulfate remains in the distillation vessel. The red fuming nitric acid obtained may be converted to the white nitric acid. The dissolved NO is readily removed using reduced pressure at room temperature (10–30 minutes at 200 mmHg or 27 kPa) to give white fuming nitric acid. This procedure can also be performed under reduced pressure and temperature in one step in order to produce less nitrogen dioxide gas. Dilute nitric acid may be concentrated by distillation up to 68% acid, which is a maximum boiling azeotrope