1. Perchloric acid is a mineral acid with the formula HClO4. It is an oxoacid of chlorine. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxidizer when hot, but aqueous solutions up to approximately 70% by weight at room temperature are generally safe, only showing strong acid features and no oxidizing properties. Perchloric acid is useful for preparing perchlorate salts, especially ammonium perchlorate, an important rocket fuel component. Perchloric acid is dangerously corrosive and readily forms potentially explosive mixtures. == History == Perchloric acid was first synthesized (together with potassium perchlorate) by Austrian chemist Friedrich von Stadion and called "oxygenated chloric acid" in the mid-1810s. French pharmacist Georges-Simon Serullas introduced the modern designation along with discovering its solid monohydrate, which he mistook for an anhydride. Berzelius produced... from wikipedia.org