Sodium hydroxide is a white solid ionic compound with the chemical formula NaOH. It dissolves easily in water, forming a slippery, soapy solution. As a strong alkali, sodium hydroxide is used in various industrial and everyday applications. Since sodium hydroxide is highly irritating to living tissues, it should be handled with care. Contact with eyes may cause permanent damage. Inhaling its vapors can also be harmful to health.
Sodium hydroxide is available in bead and flake forms. Bead caustic is denser because it is produced through compression and absorbs less moisture from the air. Flake caustic consists of finer and lighter crystals. Both forms dissolve well in water and share the same chemical properties.
Chemical and Physical Properties of Sodium Hydroxide:
- Molecular Weight: 40 g/mol
- Melting Point: 318 °C
- Boiling Point: 1390 °C
- Density: 2.13 g/cm³
- Solubility: Highly soluble in water and alcohol, low solubility in ether
Production Methods of Sodium Hydroxide:
- Electrolysis Method: This is the most common method for producing sodium hydroxide. Sodium hydroxide is obtained by the electrolysis of a sodium chloride (table salt) solution. Chlorine gas and hydrogen gas are also produced during this process. There are different types of electrolysis methods, such as the diaphragm cell method, the membrane cell method, and the mercury cell method.
- Pyrolytic Method: This is the oldest method of producing sodium hydroxide. Sodium oxide is obtained by calcining sodium carbonate at high temperatures. Sodium hydroxide is then obtained through the reaction of sodium oxide with water.
- Lime Method: This is an alternative method for sodium hydroxide production. Sodium hydroxide is obtained through the reaction of a sodium carbonate solution with lime (calcium hydroxide). Calcium carbonate is also produced as a byproduct in this process.
Applications of Sodium Hydroxide:
- Paper Industry: Sodium hydroxide plays an important role in the production of paper and paper pulp. It is used to separate cellulose fibers, dissolve lignin, and improve the whiteness and quality of paper.
- Textile Industry: Sodium hydroxide is used in textile processing and dyeing. It is utilized to process natural fibers such as cotton, wool, and silk, to produce synthetic fibers, and to enhance the solubility and fastness of dyes.
- Soap and Detergent Industry: Sodium hydroxide is one of the main components in the production of soap and detergents. It is used to saponify fatty acids, solidify soap, and enhance the cleaning power of detergents.
- Aluminum Industry: Sodium hydroxide plays a vital role in aluminum production. It is used to dissolve bauxite ore, precipitate aluminum hydroxide, and obtain metallic aluminum.
- Food Industry: Sodium hydroxide is used in the food industry for various purposes. It is used to adjust pH levels, act as a leavening agent, serve as a color stabilizer, and even as a flavoring agent. For example, sodium hydroxide is used in products such as olives, cocoa, chocolate, and cheese.
- Pharmaceutical Industry: Sodium hydroxide is also used in the pharmaceutical sector for various purposes. It is employed to increase drug solubility, prepare buffer solutions, and as an antacid.
- Biodiesel Industry: Sodium hydroxide plays an important role in biodiesel production. It is used to convert vegetable oils into methyl esters via transesterification reactions. Biodiesel is a renewable fuel developed as an alternative to fossil fuels.
At Northchem Kimya, we offer bead and flake caustic of high quality and purity at competitive prices. For your sodium hydroxide needs, feel free to contact us!