Hydrochloric acid is the aqueous solution of hydrogen chloride gas (HCl). It is a strong acid, and the major component of gastric acid. It is also widely used in industry. Hydrochloric acid must be handled with appropriate safety precautions because it is a highly corrosive solution.
Hydrogen chloride (HCl) is a monoprotic acid, which means it can dissociate (i.e., ionize) only once to give up one H+ion (a single proton). In aqueous Muriatic acid, the H+joins a water molecule to form a hydronium ion, H3O+:
HCl + H2O H3O++ Cl-