Sodium carbonate formula properties and uses

Sodium carbonate is an inorganic compound with molecular formula Na2CO3. Molecular mass of sodium carbonate is 105.99 g/mol. Sodium carbonate is also known as washing soda, soda ash and soda crystal.

Sodium carbonate is a white crystalline solid. Sodium carbonate forms three hydrates, sodium carbonate monohydrate, sodium carbonate heptahydrate and sodium carbonate decahydrate.

Sodium carbonate formula properties and uses

All forms of sodium carbonate are odorless and white in colour. Sodium carbonate is an ionic compound and hence soluble in more polar water solvent.

Density of sodium carbonate is 2.54 g/ml. The melting and boiling point of sodium carbonate are 1124K and 1873K respectively.

Sodium carbonate is an important laboratory reagent which is used in group analysis and elements analysis in organic compounds.

What is washing soda?

When soda ash is dissolved in water, one molecule of sodium carbonate combines with ten molecule of water to form sodium carbonate decahydrate and crystallized. This is known as washing soda.

Na2CO3 + 10H2O → Na2CO3.10H2O

Uses of sodium carbonate

Sodium carbonate is a very important inorganic compound. It is used in laboratory, in glass, soap and paper industry, as a precursor of many inorganic compounds and to remove hardness of water. Some uses of sodium carbonate are included here individually.

Use in glass industries

Sodium carbonate is a major ingredient in glass making. It acts as a flux for silica. Sodium carbonate is mixed with calcium carbonate and silica, and the mixture is melted to make various types of glass, such as bottle glass, window glass, etc.

Use to remove hardness of water

Sodium carbonate is used to remove temporary hardness of water in quicklime soda process. Hard water usually contains calcium or magnesium ions.

Sodium carbonate is used to remove these ions and replace them with sodium ions. As a result the hard water changes into soft water.

Use as food additive and to cooking

Sodium carbonate has several uses in cooking, as it is a stronger base than baking soda but weaker than lye. Sodium carbonate is used in the production of sherbet powder.

Sodium carbonate as a food additive in the food industry uses as acidity regulator, anticaking agent, raising agent and stabilizer. It is also used in snus production to stabilize the pH of the final product.

Use as a Precursor of other compounds

Sodium carbonate is used as a Precursor of many compounds. For example, sodium bicarbonate (NaHCO3) or baking soda is derived from sodium carbonate.

Sodium carbonate is also used to make sodium bisulfite (NaHSO3), which is used in the "sulfite" process of separating lignin from cellulose. It is also used to produce carbonates of other metals by ion exchange.

Other applications

Sodium carbonate is also used as a relatively strong alkali in various applications. As an alkali it is used in many chemical processes because it is cheaper and safer than sodium hydroxide.

Its mildness recommends its use especially in domestic applications. For example, it is used as a pH regulator to maintain the stable alkaline conditions required for developing most photographic films

It is a common addition to swimming pool and aquarium water to maintain a desired pH and carbonate hardness.

It is also used in froth flotation processes to maintain a favorable pH along with CaO and other light basic compounds as a float conditioner.

Miscellaneous

Sodium carbonate is used by the brick industry as a wetting agent to reduce the amount of water needed to extrude the clay. In casting, it is referred to as "bonding agent" and is used to allow wet alginate to adhere to gelled alginate.

Sodium carbonate is used in toothpastes, where it acts as a foaming agent and an abrasive, and to temporarily increase mouth pH.

Sodium carbonate is also used in the processing and tanning of animal hides.