What is Washing Soda

What is washing soda? It is a sodium salt of carbonic acid. You might have guessed it right; washing soda is nothing but sodium carbonate, also known as soda ash. Washing soda is largely used for the production of glass. It is used to regulate pH for maintaining stable alkaline conditions. It finds applications in chemistry, where it is used as an electrolyte. It is known as washing soda, probably because it can remove oil and alcohol stains and is hence used as a softener during laundry. How is washing soda produced?

Sources of Washing Soda

Sodium carbonate occurs naturally in arid regions. It is found in the form of deposits on locations where lakes evaporate. It is believed to have erupted from volcanoes in the past. The sodium carbonate that is mined from different parts of the United States forms the major source of washing soda. Certain salt-tolerant plant species can be used for the production of an impure form of washing soda. Washing soda occurs as a heptahydrate of a crystalline nature, which on losing its water of crystallization forms a monohydrate.

Other methods of the production of washing soda are described below.

Solvay Process

Calcium carbonate is heated to release carbon dioxide. When carbon dioxide is bubbled through a concentrated solution of sodium chloride and ammonia, sodium bicarbonate precipitates, while also producing ammonium chloride. Heating of sodium bicarbonate produces sodium carbonate or washing soda. The ammonium chloride produced in the previous reaction is treated with lime to regenerate ammonia. The replenishment of ammonia brought about through the Solvay process made it economical as compared to other methods of producing washing soda.

Hou’s Process

This process is similar to the Solvay process. However, the last step is replaced by a process of pumping carbon dioxide and ammonia into the ammonium chloride solution and adding common salt to it. The solution is saturated at 40 degrees Celsius and cooled to 10 degrees. The solution is recycled to generate sodium carbonate.

If you say, you have never seen washing soda, I must tell you; washing soda is an important constituent of most of the detergents and washing powders. Do not confuse it with baking soda; a compound that sounds to washing soda. The former is a carbonate of sodium, while the latter is its bicarbonate.