iodine disappears; sulphur is deposited in abundance, and hydriodic acid formed.
HYDRO′BENZANIDE. White crystalline mass, obtained from oil of bitter almonds by treatment with ammonia.
HYDROBRO′MIC ACID. See Bromide.
Hydrobromic Acid. (HBr.) Syn. Hydric Bromide, Hydrogen Bromide.
Prep. This very powerfully acid gaseous body may be prepared as follows:—1. By decomposing bromide of potassium with a concentrated solution of phosphoric acid. 2. By decomposing bromide of phosphorus by means of a small quantity of water.
Hydrobromic acid gas is colourless and non-inflammable; it extinguishes flame. It is extremely irritating to the lungs when breathed. It is very soluble in water.
HYDROBRO′MIDE. Syn. Bromide (which see).
HYDROCAR′BON. A compound of carbon and hydrogen. The hydrocarbons constitute a most important series of organic compounds.
HYDROCHLORIC ACID. (HCl = 36·5.) Syn. Muriatic Acid, Hydric Chloride, Hydrogen Chloride. This important gaseous compound was discovered by Priestly in 1772. In nature it is given off with other gases from active volcanoes, and is occasionally to be met with in the springs and rivers of volcanic districts. When hydrogen and chlorine are mixed in equal volumes, they are without action upon each other if kept in the dark, but if exposed to direct sunlight, chemical combination, accompanied by a loud explosion, instantly takes place between them, the result of their union being the colourless gaseous, intensely sour hydrochloric acid. If, instead of bright sunshine, the mixed gases are exposed to diffused daylight, chemical union also ensues between them, but the process is then a slow and gradual one; the passage through them, however, of the electric spark, or the application of a lighted match or taper instantly causes their explosion and combination.
One volume of chlorine unites with one volume of hydrogen, forming two volumes of hydrochloric acid; no condensation occurs in the act of union.