Understanding Bleaching Powder and Its Chemical Formula

Bleaching powder is a common chemical compound widely used for bleaching cotton and linen in the textile industry, bleaching washed clothes in laundry, and as an oxidizing agent in many chemical industries. It is also used for disinfecting drinking water, making it free of germs.

The chemical name for bleaching powder is Calcium Oxychloride. Its chemical formula represents the types and number of atoms present in one molecule of the compound.

Identifying the Correct Bleaching Powder Formula

Let's look at the given options and determine which one represents the chemical formula of bleaching powder:

• Option 1: $\text{CaCl}_2$
• Option 2: $\text{CaOCl}_2$
• Option 3: $\text{CCl}_4$
• Option 4: $\text{Ca(OH)}_2$

Analyzing each option:

• $\text{CaCl}_2$: This is the chemical formula for Calcium Chloride. It is a salt used as a drying agent and for de-icing roads. This is not bleaching powder.
• $\text{CaOCl}_2$: This is the chemical formula for Calcium Oxychloride, which is the chemical name for bleaching powder. This formula shows that the compound contains calcium ($\text{Ca}$), oxygen ($\text{O}$), and chlorine ($\text{Cl}$) atoms.
• $\text{CCl}_4$: This is the chemical formula for Carbon Tetrachloride. It is an organic compound, historically used as a fire extinguisher and refrigerant, but now less common due to its toxicity. This is not bleaching powder.
• $\text{Ca(OH)}_2$: This is the chemical formula for Calcium Hydroxide, commonly known as slaked lime. It is used in various applications, including making mortar and plaster. Bleaching powder is prepared by reacting chlorine gas with slaked lime, but $\text{Ca(OH)}_2$ itself is not bleaching powder.

Based on the analysis, the chemical formula of bleaching powder is $\text{CaOCl}_2$.

Preparation of Bleaching Powder

Bleaching powder is manufactured by passing chlorine gas over dry slaked lime.

The chemical reaction is:

$\text{Ca(OH)}_2 \text{(dry slaked lime)} + \text{Cl}_2 \text{(chlorine)} \rightarrow \text{CaOCl}_2 \text{(bleaching powder)} + \text{H}_2\text{O}$

Revision Table: Important Chemical Formulas

Additional Information on Bleaching Powder

Bleaching powder is a pale yellowish powder with a strong smell of chlorine. Its bleaching action is due to the chlorine it contains, which acts as an oxidizing agent. When bleaching powder reacts with dilute acids, it produces chlorine gas.

$\text{CaOCl}_2 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{Cl}_2$

The released chlorine is responsible for the bleaching and disinfecting properties.

Key uses of bleaching powder include:

• Disinfecting water supplies.
• Bleaching wood pulp in paper factories.
• Bleaching linen and cotton in the textile industry.
• As an oxidizing agent in the chemical industry.