Sodium Hypochlorite

CAS RN:7681-52-9

Stability / Shelf Life

Unstable in air unless mixed with sodium hydroxide.
Highly unstable; hypochlorite ion in aq soln is remarkably stable. /Pentahydrate/
The stability of sodium hypochlorite soln used as disinfectants was maintained at 4 deg for 2 yr, but after 2 yr @ 24 deg the concn of available chlorine was less than 50% of the original. A more rapid deterioration occurred in soln containing approx 100,000 ppm chlorine than in those containing 50,000 or 10,000 ppm chlorine. At pH 5-6, decomp was rapid, whereas increasing the pH increased the stability. Hypochlorites are stable if kept in a cool place, out of direct sunlight and in purpose made containers.
Two 2.5 l bottles of strong sodium hypochlorite soln (10-14% available chlorine) burst in storage, owing to failure of the cap designed to vent oxygen slowly evolved during storage.
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