The chemical formula for Bleaching powder is-

The chemical formula for bleaching powder is CaOCl₂. But to properly understand this, let’s break it down step by step with a simple and clear explanation.

Understanding Bleaching Powder

Bleaching powder is a chemical compound widely used for cleaning, bleaching, and disinfecting purposes. In everyday life, it is often seen as a white powder that smells strongly of chlorine. It is prepared by passing chlorine gas over dry slaked lime (Ca(OH)₂). This reaction produces bleaching powder.

The reaction is:

Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O

Here, we see that slaked lime reacts with chlorine gas to give CaOCl₂, which is the correct bleaching powder formula.

Detailed Explanation of the Bleaching Powder Formula (CaOCl₂)

The formula CaOCl₂ shows us that bleaching powder is made of calcium (Ca), oxygen (O), and chlorine (Cl). However, it is important to know that bleaching powder is not a simple single compound. Instead, it is a mixture that mainly contains calcium hypochlorite (Ca(ClO)₂), calcium chloride (CaCl₂), and unreacted lime (Ca(OH)₂). Because of this, many textbooks simplify it as CaOCl₂.

This structural idea explains why bleaching powder releases chlorine gas when it comes into contact with acids. For example:

CaOCl₂ + HCl → CaCl₂ + H₂O + Cl₂

So, the bleaching action of the powder is basically due to the chlorine gas that gets released during reactions.

Uses of Bleaching Powder

• Water Treatment: It is commonly added to drinking water to kill germs and make it safe to use.
• Textile Industry: Used to bleach clothes and remove stains.
• Paper Industry: For making white paper sheets by removing natural color.
• Disinfectant: Used in public places (like hospitals, drains, and toilets) for disinfection.

Why Learning the Formula Matters?

Students preparing for exams often get confused between common compounds like CaCl₂ (calcium chloride) and CaOCl₂ (bleaching powder formula). So, remembering that bleaching powder is CaOCl₂ is very important for both academic and competitive exams like JEE and NEET. A small mistake in the formula can change the meaning completely.