Nitric acid rises to 1 at a temperature of 250 °C. Nitric acid can act as a base with respect to an acid such as sulfuric acid: The nitronium ion, , is the active reagent in aromatic nitration reactions. Since nitric acid has both acidic and basic properties, it can undergo an autoprotolysis reaction, similar to the self-ionization of water: Nitric acid reacts with most metals, but the details depend on the concentration of the acid and the nature of the metal. Dilute nitric acid behaves as a typical acid in its reaction with most metals. Magnesium, manganese, and zinc liberate H:
Acetoacetic acid colour change is graded by eye. The test does not measure β-hydroxybutyrate, the most abundant ketone in the body; during treatment of ketoacidosis β-hydroxybutyrate is converted to acetoacetate so the test is not useful after treatment begins and may be falsely low at diagnosis. Similar tests are used in dairy cows to test for ketosis. Acetoacetic acid Acetoacetic acid (also diacetic acid) is the organic compound with the formula CHCOCHCOOH. It is the simplest beta-keto acid group, and like other members of this class, it is unstable. The methyl and ethyl esters, which are quite stable, are produced on a