Sep 24, 2019 · This is the chemical structure of hydrochloric acid: chlorine (green) and hydrogen (white). LAGUNA DESIGN / Getty Images. Hydrochloric acid: HCl Also known as marine acid, chloronium, spirit of salt. Hydrochloric acid is a clear, highly corrosive strong acid. It's found in diluted form as muriatic acid. The chemical has many industrial and lab uses. Muriatic acid for industrial purposes typically is 20 to 35 percent hydrochloric acid, while muriatic acid for household purposes ranges between ...