The key difference between sodium hypochlorite and bleaching powder is that sodium hypochlorite has a hypochlorite anion as the major active ingredient, whereas bleaching powder has calcium hypochlorite as the major active ingredient.
Generally, sodium hypochlorite and bleaching powder are dissolved in water before using for an intended application. These solutions can be oxidizing or reducing and give the final effect of removing dirt or germs.
CONTENTS
1. Overview and Key Difference
2. What is Sodium Hypochlorite
3. What is Bleaching Powder
4. Sodium Hypochlorite vs Bleaching Powder in Tabular Form
5. Summary – Sodium Hypochlorite vs Bleaching Powder
What is Sodium Hypochlorite?
Sodium hypochlorite is an inorganic ionic compound consisting of sodium and hypochlorite ions. It is the sodium salt of hypochlorous acid. This compound has the chemical formula NaOCl. Its molar mass is 74.44 g/mol. Generally, sodium hypochlorite is unstable and may tend to even decompose explosively. However, its pentahydrate form is stable. Moreover, its hydrated form has a pale greenish-yellow colour and occurs as a solid. Although this hydrated form is more stable than the anhydrous form, we have to refrigerate it to keep its stability. Further, sodium hypochlorite has a sweet, chlorine-like odour.
There are a few methods of preparation for this compound. We can easily prepare sodium hypochlorite via the reaction between salt (NaCl) and ozone. It is a simple method but is suitable for research purposes. For industrial needs, this compound is produced via the Hooker process. In this process, chlorine gas is passed through a dilute sodium hydroxide solution, which gives sodium hypochlorite and sodium chloride.
What is Bleaching Powder?
Bleaching powder is a powder consisting of calcium hypochlorite, and it is used mainly to remove the color from materials. The major active ingredient of bleaching powder is Calcium hypochlorite. The chemical formula of calcium hypochlorite is Ca(OCl)2.
Bleaching powder works by reacting with colored organic compounds, including natural pigments, and turning these into colorless ones. Most bleaches are oxidizing agents, whereas some are reducing agents. Besides the intended colored pigments, bleaching powder generally reacts with many other organic substances. Therefore, bleach powder can weaken or damage natural materials such as fiber, cloth, and leather.
When considering the oxidizing bleaching powder, it works by breaking the chemical bonds making up the chromophore. This can change the molecule into a different substance that can contain a chromophore, or it might contain a chromophore that does not absorb visible light. Reducing bleaching powder works by converting double bonds in the chromophore into single bonds. This can eliminate the ability of the chromophore to absorb visible light.
What is the Difference Between Sodium Hypochlorite and Bleaching Powder?
Sodium hypochlorite is an inorganic ionic compound consisting of sodium and hypochlorite ions. Bleaching powder, on the other hand, is a powder consisting of calcium hypochlorite, and it is used mainly to remove the color from materials. The key difference between sodium hypochlorite and bleaching powder is that sodium hypochlorite has hypochlorite anion as the major active ingredient, whereas bleaching powder has calcium hypochlorite as the major active ingredient.
The below infographic presents the differences between sodium hypochlorite and bleaching powder in tabular form for side-by-side comparison.
Summary – Sodium Hypochlorite vs Bleaching Powder
Bleaching agents are very important in removing dirt and germs to clean surfaces. Sodium hypochlorite and bleaching powder are two types of powdered bleaching agents, and we can use them by dissolving them in water before application. The key difference between sodium hypochlorite and bleaching powder is that sodium hypochlorite has hypochlorite anion as the major active ingredient, whereas bleaching powder has calcium hypochlorite as the major active ingredient.
Reference:
1. “Bleaching Agents.” Municipal Website Design Companies, Best City Local Government Websites CMS.
Image Courtesy:
1. “NaOCl” By Smokefoot – Own work (Public Domain) via Commons Wikimedia
2. “One teaspoon contain about 10 gram bleaching powder” By شہاب – Own work (CC BY-SA 4.0) via Commons Wikimedia