Sodium hypochlorite: Introduction, Preparation and Uses
Introduction of Sodium hypochlorite
Sodium hypochlorite (NaOCl) in solution exhibits broad-spectrum anti-microbial ( bacteria, virus, fungi, and parasites) activity and is widely used in healthcare facilities in a variety of settings. It is usually diluted in water depending on its intended use. “Strong chlorine solution” is a 0.5% solution of hypochlorite (containing approximately 5000 ppm free chlorine) used for disinfecting areas contaminated with body fluids, including large blood spills (the area is first cleaned with detergent before being disinfected). It is also known as bleach and the most common disinfectant used in medical laboratories.
Reactions for free chlorine formation:
Cl2 (g) + H2O <=> HOCl + Cl- + H+
HOCl <=> OCl- + H+ (at pH >7.6)
Three different methods of application
HOCl + NH3 <=> NH2Cl (monochloramine) + H2O
NH2Cl + HOCl <=> NHCl2 (dichloramine) + H2O
NHCl2 + HOCl <=> NCl3 (trichloramine) + H2O
Preparation of working Sodium hypochlorite
Sodium hypochlorite is also called bleach.
It is prepared by following methods
Should be diluted: 0.5%
amount of water to be added to 1 part of concentrated hypochlorite= Concentrated/dilution-1
i.e. 7 parts water and 1 part concentrated hypochlorite
It means 7 glass water and 1 glass concentrated hypochlorite.
C1= Concentrated hypochlorite or stock
V1= Volume of required stock
C2=Concentration of working solution which is required i.e. 0.5%
V1=Volume to be prepared i.e.Known-2000ml
It means 1750 ml water and 250 ml concentrated hypochlorite and final volume 20000 ml i.e. working hypochlorite.
Uses of Sodium hypochlorite
Chlorine is used in free, hypochlorite as well as chloramine forms.