Sodium hydroxide is a chemical compound with a molecular formula of NaOH or OHNa and molecular weight of 39.997 g/mol. It is a white solid at room temperature and has the ability to absorb moisture in the air. Sodium hydroxide releases significant dissolution heat when dissolved in water or acid. so that if the solution be in contact with flammable materials, it will cause fire. Sodium hydroxide is a very corrosive compound. This compound is generally used as a solution of 50% or in solid form. In generally caustic soda is used to produce petrochemical products, Paper, rayon, soap, explosive & dyestuffs. NaOH also used in manufacture of cotton, metal cleaning, bleaching & laundering. Note that if sodium hydroxide if contacted by the body, it can cause serious damage to the skin, eyes or other organs of the body.
The mono hydrate crystallizes in the space group Pbca, with cell dimensions a = 1.1825, b = 0.6213, c = 0.6069 nm. The atoms are arranged in a hydragillite-like layer structure /O Na O O Na O/… Each sodium atom is surrounded by six oxygen atoms, three each from hydroxyl anions HO− and three from water molecules. The H2 atoms of the hydroxyls form strong bonds with oxygen atoms within each O layer. Adjacent O layers are held together by hydrogen bond among water molecules.
Production of Sodium Hydroxide
Sodium hydroxide is commercially produced as a 55% solution by variations of the electrolytic chloralkali process. Chlorine gas as byproduct is also produced in this process. This product is obtained from this solution by the evaporation of water. Solid NaOH is most commonly sold as flakes, prills, and cast blocks.
Historically, sodium hydroxide was produced by reaction of sodium carbonate with calcium hydroxide in a metathesis reaction. (Caustic soda is soluble while calcium carbonate is not.)we know This process as causticizing.
Applications of Caustic soda
paper manufacturing: The paper manufacturing industry accounts for a large proportion of Sodium hydroxide use, accounting for about 25% of the hydroxides produced worldwide, Consumed in the paper industry.
Food preparation: In the food industry, sodium hydroxide is used to rinse or peel foods like cocoa, caramel, chocolate, vegetables & fruits. They also use the NaOH in the process of producing olive in order to soften them.
Cleaning agent: This compound is also commonly used as Cleaning agent in the process of the production of detergents. It can dissolved oils, protein-base materials, grease & fats. Caustic soda is used in the home as a type of drain opener to unblock clogged drains, almost in the form of a crystal or as a thick liquid gel.
Tissue digestion: NaOH is used to digest tissues, as in a process that was used with farm animals at one time. process involved placing a carcass into a sealed chamber, then adding a mixture of Caustic soda and H2O. This eventually turns the body into a liquid with a coffee appearance, and the only, solid that remains are bone hulls, which could be crushed among one’s fingertips. Caustic soda is generally used in the process of decomposing roadkill dumped in landfills by animal disposal contractors.
transesterification reagent: Sodium hydroxide is traditionally used in soap making. It was made in the 19 century for a Stiff & hard surface rather than liquid product because it was simpler to store & transport.