Sodium perchlorate is a chemical compound with the formula NaClO4. This compound, which is the sodium salt of perchloric acid, is a strong oxidizer like other perchlorates. The solubility of sodium perchlorate is the highest among other perchlorate salts. Sodium perchlorate, which consists of white crystals and is hygroscopic, is highly soluble in water and alcohol. It is usually found in monohydrate form and has a rhombic crystal structure. The standard enthalpy of formation is −382.75 kJ mol − 1.