Preparation and use of some important chemicals | Part-1

Some Important Chemicals: Preparation and Uses

In everyday life and industrial processes, various chemicals are used for specific purposes. Among them, Sodium Hydroxide (NaOH) and Bleaching Powder are two very important substances studied in Class 10 chemistry. Below is a detailed look at how they are prepared and where they are used.

1. Sodium Hydroxide (NaOH)

Preparation:

Sodium Hydroxide is manufactured through the chlor-alkali process. In this process, electricity is passed through an aqueous solution of sodium chloride (brine). This process is called **electrolysis**, and it produces three main products: Sodium Hydroxide, Chlorine gas, and Hydrogen gas.

Reaction:

2NaCl (aq) + 2H₂O (l) → 2NaOH (aq) + Cl₂ (g) + H₂ (g)

Uses:

• Used in the manufacture of soaps and detergents.
• Used in the paper and textile industries.
• Helps in refining petroleum.
• Used in making artificial fibers like rayon.

2. Bleaching Powder

Preparation:

Bleaching powder is obtained by allowing chlorine gas to react with dry slaked lime (calcium hydroxide) under normal room conditions.

Reaction:

Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O

The product formed is calcium oxychloride, commonly known as Bleaching Powder.

Uses:

• Used for bleaching cotton and linen in the textile industry.
• Used as a disinfectant for drinking water to kill germs.
• Used in the paper industry to bleach wood pulp.
• Used as an oxidizing agent in chemical industries.

Conclusion

Both Sodium Hydroxide and Bleaching Powder are vital industrial chemicals with wide applications in households, industries, and laboratories. Understanding their preparation and uses helps students connect classroom chemistry to the real world.