NITRIC ACID

This acid is a compound of 1 atom or equivalent of nitrogen = 14, and 5 of oxygen (8x5) = 40; hence its equivalent in the dry or anhydrous state, as it exists, for instance, in nitre, is 14 + 40 = 54. As it usually occurs in the liquid state, it is a compound of 1 equivalent of dry acid, 54, and 2 of water (9 x 2), 1 8; hence the equivalent of the liquid acid is 72. It is commonly known in commerce under the name of aqua fortis, and is prepared by distilling a mixture of sulphuric acid and nitre. It is commonly yellow, or even deep orange coloured; but it may be deprived of nitric oxide, which occasions this colour, by heat, and is then colourle . It is intensely corrosive and sour, fumes when exposed to air, and has a specific gravity of 1-50 when in its utmost state of concentration. It boils at 248°, and freezes at -50°. It is a most powerfully oxidizing agent, and is decomposed with more or le rapidity by almost all the metals. The salts which it forms are called nitrates; they are all soluble in water; they are decomposed by heat, and, when mixed and gently heated with sulphuric acid, they evolve nitric or nitrous acid.. NITRIC OXIDE, or [s. 839]