Sodium hydroxide (NaOH, commonly known as caustic soda, caustic soda, caustic soda. In Hong Kong, it is known as Caustic) is a white crystal at room temperature and is highly corrosive. Easily soluble in water, its aqueous solution is strongly alkaline, can make phenolphthalein red.
Sodium hydroxide is an extremely common alkali and is one of the essential medicines in a chemistry laboratory. Its solution can be used as a washing up liquid.
Chemical Performance
Colorless and transparent sodium-alkali liquid, is one of the strong bases, easily dissolved in water, can react chemically with many organic and inorganic compounds, very corrosive, can burn human skin, etc..
Sodium hydroxide is completely ionized with sodium and hydroxide ions in water, and can be neutralized with any proton acid. Take hydrochloric acid for example:
NaOH + HCl → NaCl + H2O
Sodium hydroxide is also a good catalyst for many organic reactions. The most typical of these is the hydrolysis of esters:
RCOOR' + NaOH → RCOONa + R'OH
The reaction proceeds both completely and rapidly. This is the reason why sodium hydroxide can burn the skin.
Sodium hydroxide is one of the most important ingredients in the manufacture of soap. A sodium hydroxide solution refueled with the right proportions will react and mix to become solid soap. This reaction also uses the principle of hydrolysis, and this type of ester hydrolysis catalyzed by NaOH is called saponification.
Uses
Sodium hydroxide is widely used in a variety of production processes. In chemical production, sodium hydroxide provides an alkaline environment or acts as a catalyst.Dilute solutions of NaOH can be used as a washing liquid when used at home.
In food production, sodium hydroxide is sometimes used to process food. Sodium hydroxide is even a necessary seasoning for a famous dish. Note that the use of sodium hydroxide is strictly controlled; some unscrupulous traders may overuse sodium hydroxide to make the food "look better", but such food can cause disease.
Industrial production
Sodium hydroxide is used in industry as a by-product of the chlorine production process. Saturated saline is electrolyzed until all of the chlorine has escaped as chlorine gas, at which point the only solute left in solution is sodium hydroxide. Reaction equation is:
2NaCl + H2O → 2NaOH + Cl2 + H2
Dangerous chemicals
Sodium hydroxide is a hazardous chemical in the People's Republic of China *** and the country of the "List of Dangerous Goods" (GB 12268-90), belongs to the eighth category of hazardous goods corrosive alkaline corrosive products, No. 82001. its production, operation, storage, transportation, use and disposal. Its production, operation, storage, transportation, use and disposal of waste products shall comply with the "Regulations on the Safe Management of Dangerous Chemicals".
Sodium hydroxide
General
Molecular formula NaOH
Molecular weight 40.01 g/mol
Appearance White opaque solid
CAS No. 1310-73-2
RTECS No. WB4900000
IMDG rule page no. 8225
UN No. 1823
Alias
Caustic Soda, Caustic Soda, Caustic Soda
Properties
Density at STP 2.1×103kg/m3 (?)
Solubility 111 g/100 g water
Melting point 596 K (318.4 °C)
Boiling point 1663 K (1390 °C)
Hazardous
Ingesting Severe and permanent damage to the digestive system, mucous membrane erosion, hemorrhage, shock.
Inhalation Irritation of respiratory tract, corrosion of nasal septum
Skin Danger. Can cause burns up to symptoms of severe ulcers.
Eyes Danger. Can cause burns or even damage to the cornea or conjunctiva.
Handling
Hazard:
Strongly corrosive
Personal protection:
Wear gas masks, chemical safety glasses, anticorrosive coveralls, and rubber gloves
Prone to reaction:
Reacts heavily exothermically with water and water vapors to form corrosive liquids, and reacts with acids in a neutralization reaction with an exotherm. exothermic.
Storage:
Avoid contact with humid air, store separately from flammable and combustible materials and acids.