Bleaching Powder and Sodium Hydroxide - Overview, Preparation, Formula, Uses, FAQs

Bleaching powder is the general name of the compound for calcium hypochlorite with a chemical formula CaOCl₂. Using it is so wide that it plays a critically important role in many sectors. Its role in the daily routine is more than people think. It is mostly in various cleaning products available at home, and in water treatment plants, it is an industrial version of a strong disinfectant and bleaching agent. It therefore has such highly potent oxidizing properties to destroy bacteria, viruses, and fungi that can impact public health and safety and thus cannot be avoided. For instance, bleaching powder is used for the treatment of drinking water in most parts of the world, especially where there is a prevalence of water-borne diseases, reducing health risks that are ever so eminent from sources of contamination. Further, it will explore how relevant the associable aspects, together with the diverse types of bleaching agents derivable from the bleaching powder, are in common situations. The intention is to give, at the end of this debate, the reader some good insight into the bleaching powder and something of the importance involved with it, both in the scientific and practical arena

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This Story also Contains

1. Physical Properties of Bleaching Powder
2. Applications and Relevances of Bleaching Powder
3. Summary

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Physical Properties of Bleaching Powder

It is a white, odourless powder, which is very soluble in water, which it fuses without decomposition, giving a strongly alkaline solution. Finally, with a molecular formula of Ca2, both the calcium ions and the hypochlorite ions are responsible for the bleaching and disinfecting action. This compound boils at 350 to 100 °C, and its density is about 2.35 g/cm³. One major characteristic of bleaching powder that gives it the advantage of killing bacteria effectively and every sort of any other pathogen is the fact that it is highly oxidizing. This should also take into account the fact that it is stable by virtue of environmental conditions like temperature and humidity which may make it liberate harmful chlorine gas in case it is not stored properly. Advanced Physical Properties of Bleaching Powder Rogers. An appreciation of those advanced physical characteristics is essential for the proper uses of bleaching powder in the various application.

For example, it reacts to release chlorine gas upon mixing with an acid. This goes on to prove that it has the oxidizing capacity; however, above all, the greatest care must be taken while handling it. Besides, bleaching powder is hygroscopic; it absorbs water when exposed to the atmosphere. It, therefore, loses its potency over time. The compound reactivity also brings about different natures of the bleaching agents, among which, is sodium hypochlorite, a rather significantly extendable application as household bleach. Some subtleties in using a compound are given in them and have quite a number; therefore, one must have quite a deep knowledge of its properties to be able to use it properly and carefully.

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Preparation

• It is a mixture of CaCl₂ and Ca(OCl)₂.
• It is manufactured in Bachmann's plant.
• The chemical reaction for the preparation of bleaching powder is as follows:
• Ca(OH)2+Cl2→CaOCl2+H2O

Physical properties

• It is a yellowish-white powder with the smell of chlorine.
• Most of it is soluble in water but a small amount is insoluble in lime.

Chemical properties

• Reaction with insufficient and excess dilute acid:
• CaOCl2+H2SO4→CaSO4+CaCl2+2HCl+O2
• Autoxidation: When it undergoes autoxidation, it loses its available chlorine due to which affects its bleaching process.
• 6CaOCl2→5CaCl2+Ca(ClO3)2
• Catalytic decomposition: The catalytic decomposition of bleaching powder occurs as follows:
• 2CaOCl2→CoCl22CaCl2+O2

Uses

• It is an oxidizing agent.
• It is a chlorinating agent.
• It is used as a disinfectant.
• It sterilizes water.

Related Topics link

• Introduction to P Block Elements
• K2Cr2O7
• Borax Formula
• Boric Acid
• Sulfuric Acid
• Phosphoric Acid

Applications and Relevances of Bleaching Powder

Its applications are far-reaching from its simple use as a bleacher. It is tapped for water disinfection to render it potable to millions of people. With good disinfection properties, it is invaluable to public health, especially in areas where many of these diseases are water-borne. This element also finds applications in textile industries for the extraction of color from the fabric so that whiteness can be introduced, and in the making of papers as a bleaching agent. Bleaching holds paramount importance in sanitization before use by equipment or surfaces in the food industry. They learn bleaching powder to understand chemical reactions and processes of oxidation and, more importantly, how to deal safely with the chemicals to their user. For instance, the value of bleaching powder in real life may be more relevant if, through case studies, water purification was undertaken during disaster management. In general, bleaching powder works in these major ways across sectors, depicting quite practical implications and relevance to academics.

Recommended topic video on(bleaching powder)

Some Solved Examples

Example 1
Question:

When PbS is oxidized by Cl₂ it forms

1) (correct)PbSO₄

2)SO₂

3)SO₃

4)S

Solution:

Cl₂ oxidizes PbS to PbSO_4,

The reaction is given as 4Cl2+PbS+4H2O→PbSO4+8HCl

Hence, the answer is the option (1).

Example 2
Question:

Cl2+Hg2Cl2→ Product

The product is

1)Hg

2) (correct)HgCl₂

3)[HgCl₄]^2-

4)HgCl
Solution:

As we have learnt,

Reaction with Mercury (I) Chloride with Chlorine -Chlorine oxidizes Mercurous ions to mercuric ions

Cl2+Hg2Cl2→2HgCl2

Hence, the answer is the option (2).

Example 3
Question:

With which substance should chlorine be treated to get bleaching powder

1)Sodium hydroxide

2) (correct)Calcium hydroxide

3)Potassium hydroxide

4)Sodium carbonate

Solution

As we have learnt,

When calcium hydroxide is treated with chlorine gas, it yields bleaching powder.

The reaction is given as

2Ca(OH)2+2Cl2→CaCl2+Ca(OCl)2+2H2O

Hence, the correct answer is Option (2)

Summary

Bleaching powder happens to be a very important chemical in various applications both in routine daily life and in industries. Its physical properties significantly impact the working of the chemical as a bleaching and disinfectant agent, including properties such as solubility, density, and stability. The knowledge of the different issues concerning its reactivity and risks is quite important for safe and sustainable operation with bleach powder. Its importance cuts across to water treatment, textiles, food safety, and education. This knowledge comes cemented with the bleaching powder in present-day sanitation and industrializing practices.

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