Soolhappe

Soolhappe, known in English as hydrochloric acid, is an inorganic compound with the chemical formula HCl. In its pure form it is a colorless gas with a sharp, irritating odor; when dissolved in water it forms hydrochloric acid, a strong mineral acid widely used in industry and the laboratory. Concentrated solutions are colorless liquids with a strong corrosive character.

Soolhappe is primarily produced industrially by generating hydrogen chloride gas and absorbing it in water. Common laboratory and commercial methods include the reaction of hydrogen chloride with water or the gas-phase reaction of chlorine with hydrogen in the presence of catalysts to form HCl. In industry, hydrogen chloride is often obtained as a byproduct of chlorination processes or fossil-fuel combustion.

In nature, hydrochloric acid occurs in gastric juice of humans and many other animals, where it aids digestion. Outside living organisms, it is not found free; it is manufactured and handled as an aqueous solution.

Applications include metal pickling and surface finishing, ore concentration, production of organic chlorides, and pH adjustment in chemical processes. It is also used in food processing as a processing aid in small amounts (E507 in some regulatory frameworks) and in laboratory titrations.

Safety and handling: hydrochloric acid is highly corrosive and irritant to skin, eyes, and the respiratory tract. It reacts with bases to form salts and water and with reactive metals to release hydrogen gas. It must be stored in corrosion-resistant containers, away from bases and oxidizers, with proper ventilation and personal protective equipment.

History and naming: the term hydrochloric acid reflects its composition from hydrogen and chlorine; the older name muriatic acid is still encountered in some contexts.