|Formula weight||36.5 amu|
|Melting point||159 K (-114 °C)|
|Boiling point||188 K (-85 °C)|
|Solubility||70 g in 100g water|
|S0gas, 1 bar||186.9 J/mol·K|
|S0liquid, 1 bar||? J/mol·K|
|Ingestion||Toxic, can be fatal.|
|Inhalation||Fumes may be fatal. Do not give unprotected mouth-to-mouth resuscitation.|
|Skin||May cause severe burns.|
|More info||Hazardous Chemical Database|
The chemical compound hydrochloric acid is a highly acidic aqueous solution of hydrogen chloride (HCl). It is highly corrosive and should only be handled with appropriate precautions. Hydrochloric acid is a commonly used chemical reagent and is one of the strong acids that ionize completely in aqueous solution. Concentrated hydrochloric acid has a pH of less than 1.
An old (pre-systematic) name for hydrochloric acid is muriatic acid, from before the discovery of the element chlorine and the establishment of the acid's formula as HCl. It is still sold by industrial suppliers and hardware stores under the old name for removing mortar stains and film from brick, masonry, and stone work. The adjective muriatic means "pertaining to brine or salt", presumably from the chlorine component.
Hydrochloric acid was known to alchemists as 'spirit of salt' or acidum salis. Gaseous HCl was called 'marine acid air'.
Aqua regia is an old name for a mixture of hydrochloric and nitric acids.
Human digestive fluids consist of a mixture of hydrochloric acid and various enzymes which help break down stomach contents.