Facts of Sodium Hydroxide

The chemical compound sodium hydroxide (NaOH) has the formula NaOH. Sodium hydroxide is another name for it. It is made up of sodium cations Na+ and hydroxide anions OH and is white in colour. Ascarite, White caustic, and Sodium hydrate are some of the other names for sodium hydroxide. Its molar mass is 39.9971g/mol and its formula is NaOH. It has the appearance of a white, waxy, opaque crystal with no odour. It has a density of 2.13 grammes per cubic metre. Glycerol is soluble, ammonia is negligible, ether is insoluble, and propanediol is slowly soluble.

Sodium Hydroxide ( Caustic Soda )

Sodium hydroxide, often known as caustic soda, is a very caustic base and alkali that decomposes proteins at room temperature and can result in serious chemical burns. It collects moisture and CO2 from the air and is extremely soluble in water. It breaks down into a succession of hydrates, such as NaOH.nH2O.

Sodium hydroxide is used in a variety of sectors, including pulp and paper, textiles, beverages, soaps and detergents, and drain cleaning.

Physical Characteristics

Unblendable on a physical level NaOH is a crystalline solid that is colourless. It has a melting point of 318 degrees Celsius (604 degrees Fahrenheit) and a boiling point of 1,388 degrees Celsius (2,530 degrees Fahrenheit). Water is extremely soluble, however polar solvents like ethanol and methanol have a lesser solubility. In ether or other non-polar solvents, NaOH does not dissolve. The mechanism of saponification that occurs between NaOH and natural skin oils causes it to feel slippery when it comes into touch with the skin.

Viscosity

The viscosity of aqueous NaOH, like that of any other liquid chemical, is inversely proportional to its service temperature, i.e., it reduces as temperature rises and vice versa. Caustic soda solutions have a viscosity that affects both their application and storage.

Hydrates

The hydrates NaOH.nH2O that sodium hydroxide can produce result in a fancy solubility diagram. The following are the known hydrates, as well as the approximate temperature and concentration (mass percent of NaOH) of their saturated water solutions.

Structure of the crystal 

Orthorhombic crystals are formed by NaOH and other monohydrates. It belongs to the space groups Cmcm and Pbca. A hydrargillite-like layer structure ( O Na O O Na O ) is used to organise the atoms. Each NaOH atom has six oxygen atoms surrounding it, three from hydroxyl anions OH and three from water molecules. The hydroxyls’ hydrogen atoms establish strong connections with the oxygen atoms within each O layer.

Chemical Properties :

Reaction with Acid:

Caustic soda combines with protic acids to produce water and, as a result, salts. When caustic soda combines with acid, for example, common salt is formed:

NaOH (aq) + HCl (aq)  →  NaCl (aq) + H2O (l)

This type of reaction, when performed with a strong acid, produces heat and is thus exothermic.

Reaction with Acidic Oxides

Acidic oxides, such as sulphur dioxide, react with sodium hydroxide. These reactions are frequently used to “scrub” dangerous acidic gases (such as SO2 and H2S) created during coal combustion, preventing their discharge into the atmosphere. As an example,

 2NaOH+SO2  →  Na2SO3+H2O

At room temperature, glass reacts slowly with aqueous NaOH or caustic soda solutions to form soluble silicates. Because iron lacks amphoteric characteristics, NaOH has no interaction with it at ambient temperature. Iron can, however, react endothermically with caustic soda at high temperatures (over 500 °C) to produce iron(III) oxide, sodium metal, and hydrogen gas.

Consider what happens when molten NaOH meets finely split iron filings:

4Fe + 6NaOH  →  2Fe2O3  + 6Na + 3H2

Saponification

For the hydrolysis of esters such as amides and alkyl halides, sodium hydroxide is commonly used. Despite its solubility in propanediol, it is unlikely to exchange water during saponification due to the propanediol’s principal reaction with fat occurring before the reaction with caustic soda.

Production

Sodium hydroxide is generated as a 50 percent solution for industrial use using versions of the electrolytic chloralkali process. During this procedure, chlorine gas is produced. The evaporation of water yields solid caustic soda from this solution. Solid NaOH is usually sold in the form of flakes, prills, or cast blocks.

NaOH has traditionally been made by reacting washing soda with lime in a metathesis process, which takes advantage of the fact that NaOH is soluble whereas carbonate is not. It’s used to purify the bauxite ore, which is used to make aluminium metal. The Bayer process is what we’re talking about here.

1. Sodium hydroxide is a widely used strong base in industry.

2. NaOH is used to make sodium salts and detergents, as well as for pH adjustment and organic synthesis.

3. It’s most commonly handled as a solution in bulk.

4. In the petroleum business, caustic soda is used as a drilling fluid addition to increase the alkalinity of bentonite mud systems, increase mud viscosity, and neutralise acid gas.

5. It is used in the manufacture of soaps and detergents.

6. It is also used in the production of artificial textile fibres (such as Rayon) and paper.

7. Industry uses 56% of the caustic soda generated, with the paper industry accounting for 25% of the total.

8. It is widely used for degreasing metals, oil refining, and the production of colours and bleaches.

Storage

Caustic soda must be handled with caution, especially in bulk quantities, because it can cause chemical burns. NaOH is often stored in bottles for small-scale laboratory use, intermediate bulk containers (medium volume containers) for cargo handling and transit, or huge stationary storage tanks with quantities up to 100,000 gallons for manufacturing or wastewater plants that utilise NaOH extensively.

Polyethylene (HDPE, common, XLPE, less common), steel, PVC (PVC), chrome steel, and fibreglass-reinforced plastic are all typical materials that are compatible with caustic soda and are sometimes used for NaOH storage (FRP, with a resistant liner).

Conclusion 

We conclude that soaps, rayon, paper, explosives, colours, and petroleum products are all made with sodium hydroxide. It can also be used for cotton fabric processing, metal cleaning and processing, oxide coating, electroplating, and electrolytic extraction, among other things.