The Story of Washing Soda Na₂CO₃ 10H₂O

Sodium Carbonate Washing Soda

The washing soda chemical name is sodium carbonate. Pure sodium carbonate is a white, odourless powder that is hygroscopic means it absorbs moisture from the air.

The chemical formula of sodium carbonate is Na2CO3 and its molar mass is 106g/mol. It is an ionic compound- a sodium salt of carbonic acid and is composed of two sodium and one carbonate ion. 

Washing soda is hydrated sodium carbonate. The washing soda formula is Na2CO3.10H2O.

In this article, we will study sodium carbonate washing soda in detail.


Properties of Washing Soda


1. Physical Properties

  • It is present in the form of monohydrated salts (Na2CO3.10H2O), anhydrous salts (Na2CO3), hepta-hydrous salts (Na2CO3.7H2O), and deca-hydrous salts.

  • Colour - greyish white powder

  • Odour- odourless

  • Taste- alkaline taste

  • Melting point- 851

  • Boiling point- decomposes

  • Density - 2.54

  • Stability- stable at ordinary temperature and atmospheric conditions, dries out in warm.

2. Chemical Properties

  • It is stable but hygroscopic solid and readily dissolves in water to form slightly acidic carbonic acid and strong base sodium hydroxide. The aqueous solution of sodium carbonate is a strong base. It reacts violently with many acids, it decomposes to emit toxic fumes of disodium oxide.

Formation of Washing Soda


Solvay Process

This process is used for the manufacturing of washing soda. Here we will study the chemical equation of washing soda.

Materials required

  1. Sodium chloride

  2. Limestone

  3. Ammonia gas

It consists of four steps-

  1. Purification of Brine

  2. Formation of sodium hydrogen carbonate

  3. Formation of sodium carbonate

  4. Recovery of ammonia


Step1: Purification of Brine

  • At the first stage, a saturated solution of sodium chloride is prepared which is known as brine.

  • Brine is concentrated through evaporation. Impurities are removed through precipitation.

  • Sodium chloride brine is the first purified scaling of downstream process equipment and to prevent the contamination of the final product.

  • After removing the impurities, brine solution is then filtered and passed through an ammonium tower to dissolve ammonia. After purification, brine is contacted with ammonia gas.

Step 2: Formation of Sodium Hydrogen Carbonate

  • The ammoniated brine is then sent to the carbonating columns where sodium carbonate is precipitated by contacting the brine with carbon dioxide.

NH₃(aq) + CO₂(g) + NaCl(aq) +H₂O → NaHCO₃(s) + NH₄Cl(aq)

Step 3: Formation of sodium carbonate:

  •  The suspended sodium hydrogen carbonate is removed from the carbonating tower and treated at 300C to produce sodium carbonate. 

2NaHCO → NaCO + CO + HO

  • This carbon dioxide is recycled back into the carbonating tower.

Step 4: Recovery of ammonia: 

2NH₄Cl + Ca(OH)₂ → 2NH₃ + CaCl₂ + H₂O

  • The ammonia is recycled back into the process to form ammoniated brine. Calcium chloride is formed as a by-product of the Solvay process.

Uses of Washing Soda

  1. Used in industries and households as a cleaning agent. 

  2. It finds its use in the industries of paper, textiles, soap, and detergent. 

  3. It is used in the process of water softening. 

  4. It is used in glass production. 

  5. It is one of the laundry agents of greatest significance.


Did You Know?

The ashes of burned plants are one common source of washing soda; for this reason, it is often called soda ash.

Light and dense soda ash are typically wrapped in multi-wall paper containers, plastic, or polyethylene lined bags. Covered bottom discharge hopper cars are the most common rail cars used for bulk soda ash. 

Sodium carbonate is a brittle, crystalline substance that is susceptible to conveyor equipment breakage. Soda ash produces particles that are micron-sized and require high-efficiency collectors. 

Usually, soda ash is processed in a factory for a limited period. As a pile on the floor, it can be packed in bulk and retrieved by a front-end loader or other bulk-handling unit.

FAQs (Frequently Asked Questions)

Question: Is Washing Soda a Disinfectant?

Answer: Due to its disinfectant properties and ability to cut through grease and soften water, sodium carbonate is used in many cleaning products, including green cleaning ones.

Question: What Does Washing Soda Consist of?

Answer: Washing soda is sodium carbonate. Washing Soda formula is (Na₂CO₃). Typically made from limestone and salt, it is a natural material. It's very alkaline (pH11), so avoid skin and eye contact.

Question: Is Laundry Soda Equivalent to Washing Soda?

Answer: Commercial detergents for laundry never contain borax and washing soda together. This is an either/or type of thing. Powder laundry detergents typically have washing soda in their formula, while borax, usually with alcohol, is a liquid laundry detergent (plus other chemicals)