Understanding Washing Soda and its Chemical Name

The question asks us to identify the chemical compound commonly known as washing soda from the given options. Washing soda is a well-known household chemical used for cleaning purposes, particularly for laundry.

What is Washing Soda?

Washing soda is the common name for hydrated sodium carbonate. It is a salt formed from sodium and carbonic acid. Its chemical formula is typically written as Na₂CO₃·10H₂O, indicating that it is sodium carbonate with ten molecules of water of crystallization. Anhydrous sodium carbonate (Na₂CO₃) is also sometimes referred to as soda ash.

Washing soda is a basic salt and forms alkaline solutions in water, which helps in removing grease and dirt. It is effective in softening hard water by precipitating calcium and magnesium ions.

Analyzing the Options

Let's look at the provided options and determine which one corresponds to washing soda:

1. Calcium carbonate
2. Calcium bicarbonate
3. Sodium carbonate
4. Sodium bicarbonate

1. Calcium Carbonate

Calcium carbonate has the chemical formula CaCO₃. It is a common substance found in rocks like limestone, marble, and chalk. It is used in various applications, including as a building material, an antacid, and a filler in paper and plastics. Calcium carbonate is not washing soda.

2. Calcium Bicarbonate

Calcium bicarbonate is a compound that exists only in aqueous solutions, typically formed when carbon dioxide dissolves in water containing calcium carbonate. It is a major component responsible for temporary hardness in water. Its formula is Ca(HCO₃)₂. Calcium bicarbonate is not washing soda.

3. Sodium Carbonate

Sodium carbonate has the chemical formula Na₂CO₃. As discussed earlier, sodium carbonate (especially in its hydrated form, Na₂CO₃·10H₂O) is commonly known as washing soda. It is widely used as a cleaning agent, water softener, and in manufacturing processes like glassmaking.

4. Sodium Bicarbonate

Sodium bicarbonate has the chemical formula NaHCO₃. It is commonly known as baking soda. It is used in baking as a leavening agent, as an antacid, and in fire extinguishers. Sodium bicarbonate is not washing soda.

Conclusion

Based on the analysis of the options, the chemical compound known as washing soda is Sodium carbonate.

Revision Table: Common Chemicals

Additional Information: Properties and Uses of Sodium Carbonate

Sodium carbonate, or washing soda, is an important industrial chemical. Some key points about it include:

• It is a white, odorless powder.
• It is soluble in water, forming a strongly alkaline solution (pH typically around 11).
• It can be produced from sodium chloride (common salt) and limestone through processes like the Solvay process.
• Besides cleaning and water softening, it is used in the manufacture of glass, paper, detergents, and textiles.
• It can absorb moisture from the air, forming the decahydrate (Na₂CO₃·10H₂O), monohydrate (Na₂CO₃·H₂O), or even remaining anhydrous depending on conditions.