Hydrogen Chloride

The alchemists of medieval times first prepared hydrogen chloride by heating ordinary salt ( sodium chloride) with iron sulfate. The German chemist Johann Glauber (1604-1668) made hydrogen chloride by the reaction of salt with sulfuric acid, and this became the common method for conveniently preparing hydrogen chloride in the laboratory. By passing hydrogen chloride gas into water, hydrochloric acid is produced. Because hydrogen chloride was first prepared from salt, hydrochloric acid was originally referred to as spirits of salt. Commercially, it was also commonly called muriatic acid, from the Latin muria, meaning brine, or salt water. Hydrochloric acid dissolves many substances, and the alchemists found this acid to be very useful in their work. For example, it was used to dissolve insoluble ores thereby simplifying the methods of chemical analysis to determine the metal content of the ores. A mixture of hydrochloric acid and nitric acid (known as aqua regia) also became very useful since it was the only acid that will dissolve gold.