Uses of Sodium carbonate

Sodium carbonate is used in the manufacture of glass (55%), pulp and paper (5%), soap, and many other chemicals (25%) such as sodium silicates and sodium phosphates. It is also used as an alkaline agent in chemical industry.

Domestically it is used as a water softener during laundry. It competes with the ions magnesium and calcium in hard water and prevents them from bonding with the detergent being used. Without using washing soda, additional detergent is needed to soak up the magnesium and calcium ions.

Sodium carbonate is also used in a photographic process known as reticulation. A film negative can be placed in a hot bath of sodium carbonate which may cause the metallic silver to clump and the emulsion to separate from the base of the film, producing a cracked and abstracted image.

Sodium carbonate is also used by the brick industry as a wetting agent to reduce the ammount of water needed to extrude the clay.