How stable is sodium hypochlorite?
The concentration of sodium hypochlorite would therefore remain above 90% of the initial concentration for 22.9 months. It is concluded that sodium hypochlorite solution stored in amber-glass bottles should carry a 23-month expiry date on chemical stability.
How long does it take sodium hypochlorite to degrade?
Sodium hypochlorite is highly reactive and volatile. At normal pH (6-8), sodium hypochlorite can degrade substantially within 2-3 weeks.
How do you stabilize sodium hypochlorite solution?
A process for stabilizing the solution of sodium hypochlorite includes such steps as regulating pH value of said solution, adding 8-hydroxy quinoline, and stirring in sealed condition.
How should sodium hypochlorite be stored?
Sodium hypochlorite should be stored separately from incompatible materials. Store chemicals such as reducing agents, organic materials and acids away from bleach. Sodium hypochlorite storage needs to be at temperatures below 68 F (20 C) in air-tight bottles.
Why is hypochlorite unstable?
Unstable compound Sodium hypochlorite is unstable. When sodium hypochlorite dissolves in water, two substances are formed that play a role in oxidation and the disinfection processes. These are hypochlorous acid and the less active hypochlorite ion. The pH of the water determines how much hypochlorous acid is formed.
What happens when sodium hypochlorite is added to water?
When sodium hypochlorite is added to water, it forms an OCl- (hypochlorite) ion that is called free chlorine. This ion should not be confused with chlorine gas. Free chlorine is what most municipal water treatment facilities use for disinfection.
How corrosive is sodium hypochlorite?
Corrosion The high pH of hypochlorite will attack metals. It will generate hydrogen gas when in contact with aluminum. Pipe leaks can emit chlorine gas and cause corrosion on nearby metal. Decomposition Metal contact causes catalytic decomposition of hypochlorite to oxygen gas and sodium chloride.
Where do you store hypochlorite?
Sodium hypochlorite is best stored for the longest storage life at temperatures around or below 60°F (15°C), when filtered and free of impurities, at dilute concentrations that maintain pH above 10, and without direct sun exposure due to the decomposition effects of ultraviolet radiation and heat.
Which is better low or high concentration hypochlorite?
Low concentration hypochlorite solutions decompose slower than high concentration hypochlorite solutions. Fifteen weight percent sodium hypochlorite will decompose approximately 10 times faster than 5 wt% sodium hypochlorite at 25°C. The pH has a significant effect on the stability of sodium hypochlorite solutions.
What is the stability test for sodium hypochlorite?
• The product must satisfy a stability test: Heat at 70°C for 4 hours and still have a minimum of 96g/L available chlorine. The degradation of sodium hypochlorite is proportional to its concentration. Stronger concentrations degrade faster than more dilute ones.
How are sodium hypochlorite 1% solutions stored?
Sodium hypochlorite 1% solutions were diluted (1:8, 1:12, and 1:20) and stored at room temperature in a window exposed to sunlight in amber-glass, two-liter bottles that were two-thirds full. Samples were taken 25 times throughout a six-month study period; bottles were opened only on sampling days.
Which is more stable sodium hypochlorite or hypochemical acid?
STABILITY Although more stable than hypochlorous acid, sodium hypochlorite is unstable. It starts decomposing immediately. With proper care, the rate of decomposition can be reduced such that relatively stable solutions can be prepared. The stability and shelf life of a hypochlorite solution depends on five major factors: