Sodium hydroxide, also known as caustic soda or leach, has the chemical formula NaOH. As a form of aggregation, it is a solid, hygroscopic, white body. Soda is a strong base (pH=14 at c=1 mol/l), it easily dissolves in water with heat release. It reacts with carbon dioxide in the air, resulting in sodium carbonate, so caustic soda is stored in airtight containers to avoid contact with air or moisture.
Sodium hydroxide is used in large quantities in many industries, especially as an aqueous solvent.
It is used for:
- Obtaining cellulose and paper from wood or straw,
- Chemicals and plastics,
- Manufacture of soap and detergents,
- Manufacture of dyes,
- Synthesis of artificial textile fibres,
- Mercerization of cotton (cotton becomes silkier, easier to dye, stronger)
- Aluminium production (bauxite processing)
- Oil, grease and petroleum cleaning
- Chemical refining of cooking oil
- In obtaining bauxite aluminium
- Chemical synthesis of various products, such as: sodium hypochlorite, sodium phosphate, sodium sulphite, sodium aluminate
- Formic acid synthesis
- In electronics: production of conductive plates (approx. 10g/l at 20 °C)
- It is a component of pipe cleaners
- The caustic property is used in the treatment of copper plates for pattern manufacturers
- Cleaning stainless steel or metal containers
- Dye removal
- Demineralized water production: to regulate pH and regenerate the exchange of stationary ions in resins when treating water.