Short Answer

Bleaching powder (Ca(OCl)₂) is a chemical compound widely used as a disinfectant, bleaching agent, and sanitizer. It is prepared by reacting chlorine gas with dry slaked lime (Ca(OH)₂).

It is commonly used in water purification, laundry, bleaching of clothes, and sanitation in hospitals and public places. Its strong oxidizing property makes it effective for killing bacteria and removing stains.

Detailed Explanation :

Introduction to Bleaching Powder

Bleaching powder, chemically calcium oxychloride (Ca(OCl)₂), is a white or slightly greenish powder. It is produced by the reaction of chlorine gas with slaked lime:

Ca(OH)₂ + Cl₂ → Ca(OCl)₂ + H₂O

It contains available chlorine which gives it strong oxidizing and disinfectant properties.

Composition and Properties

• Chemical formula: Ca(OCl)₂
• Appearance: White or greenish powder
• Odor: Strong chlorine smell
• Solubility: Slightly soluble in water
• Nature: Strong oxidizing agent, alkaline in nature

Properties:

1. Reacts with acids to liberate chlorine gas:
   Ca(OCl)₂ + 2HCl → CaCl₂ + Cl₂ + H₂O
2. Acts as a bleaching agent due to oxidizing ability.
3. Kills bacteria and pathogens effectively, making it a disinfectant.

Uses of Bleaching Powder

1. Water Purification

• Bleaching powder is added in low concentrations to drinking water to kill germs and bacteria.
• Ensures safe and potable water.
• Commonly used in municipal water supply and swimming pools.

2. Bleaching of Textiles and Paper

• Used in the textile industry to bleach cotton and linen fibers.
• In paper manufacturing, it is used to whiten paper pulp.
• Acts by oxidizing colored compounds to make fabrics and paper appear white.

3. Disinfection and Sanitation

• Used in hospitals, kitchens, bathrooms, and drains as a disinfectant.
• Helps prevent spread of bacteria and diseases.
• Common in slurry form for cleaning toilets and public spaces.

4. Laundry Uses

• Small amounts added to wash water help remove tough stains and whiten clothes.
• Effective in oxidizing organic stains on fabrics.

5. Agricultural Uses

• Used to disinfect soil and animal sheds, killing bacteria and pathogens.
• Helps maintain hygiene in poultry farms and livestock areas.

Preparation and Chemical Reaction

1. Reaction with Slaked Lime:
   • Dry slaked lime reacts with chlorine gas at room temperature:
     Ca(OH)₂ + Cl₂ → Ca(OCl)₂ + H₂O
2. Reaction with Water:
   • Bleaching powder liberates hypochlorous acid (HOCl) in water, which acts as a bleaching and disinfecting agent:
     Ca(OCl)₂ + H₂O → Ca(OH)₂ + HOCl
3. Oxidizing Action:
   • The hypochlorite ion (OCl⁻) oxidizes stains and destroys microorganisms.
   • Responsible for disinfectant and bleaching properties.

Safety Considerations

• Corrosive and irritant: Can irritate skin, eyes, and respiratory tract.
• Storage: Must be kept in a dry, cool place away from acids.
• Handling: Use gloves and masks when handling concentrated powder.
• Do not mix with acids or ammonia, as it can release toxic chlorine gas.

Summary

• Bleaching powder (Ca(OCl)₂) is an important chemical in daily life.
• Its oxidizing and disinfectant properties make it suitable for:
  • Water purification
  • Textile and paper bleaching
  • Sanitation and disinfection
  • Laundry and stain removal
  • Agricultural hygiene
• It is prepared by reacting chlorine with slaked lime.
• Safety precautions are necessary due to its strong oxidizing nature.

Conclusion

Bleaching powder is a versatile chemical compound used in households, industries, and agriculture. Its oxidizing and disinfectant properties make it essential for water treatment, bleaching, cleaning, and sanitation. Proper handling ensures safe and effective use, making it a vital chemical in both domestic and industrial applications.