次亜塩素酸ナトリウム
Sodium hypochlorite (commonly known in a dilute solution as bleach) is a chemical compound with the formula NaOCl or NaClO, comprising a sodium cation () and a hypochlorite anion (or ). It may also be viewed as the sodium salt of hypochlorous acid. The anhydrous compound is unstable and may decompose explosively. It can be crystallized as a pentahydrate ·5, a pale greenish-yellow solid which is not explosive and is stable if kept refrigerated.