HClO4 (perchloric acid) is a stronger acid than HClO3 (chloric acid). In fact HClO4 is considered to be the strongest of all known acids. Both HClO4 and HClO3 are oxyacids of chlorine, and the oxidation number of chlorine in them are +7 and +5 respectively.What does HClO4 mean?
noun Chemistry. a colorless, syrupy hygroscopic liquid, HClO4, an acid of chlorine containing one more oxygen atom than chloric acid: used chiefly as a reagent in analytical chemistry.What is the pKa of HClO4?
HClO4 is more acidic by around 7 pKa units. HClO4 because central atom (chlorine) is more electronegative than iodine. Besides, periodic acid is highly unstable and in fact has formula: H5IO6. Perchloric acid is one of the strongest mineral acids (stronger than 100% H2SO4).