Sodium hydroxide, or caustic soda, is an inorganic compound that belongs to the class of bases, or hydroxides. Also in technology and abroad, this substance is called caustic soda. The trivial name - caustic soda - it received because of its strong corrosive effect.
It is a hygroscopic white crystalline solid that melts at 328 degrees. Sodium hydroxide is highly soluble in water and is a strong electrolyte. When dissociated, it decomposes into a metal cation and hydroxide ions.
When dissolved in water, it forms an active substance - alkali, - soapy to the touch. This reaction proceeds very rapidly - with splashing and heat release. It is the ingress of alkali on the skin and mucous membranes that causes severe chemical burns, therefore, when working, you must be careful and protect your hands and eyes. If this substance gets into the epithelium or into the eyes, mouth, it is necessary to wash the affected areas with water and a weak solution of acetic (2%) or boric (3%) acid as soon as possible, and then again with water. After providing emergency care, the victim must be seen by a doctor.
Sodium hydroxide (chemical formulacompounds - NaOH, structural - Na-O-H) is a chemically active substance that can react with both inorganic and organic substances. A qualitative reaction to the hydroxide ion with various indicators will help to detect it in aqueous solutions. So, the litmus indicator becomes dark blue, methyl orange - yellow, and phenolphthalein - crimson, while the intensity of the color will depend on the concentration of alkali.
Sodium hydroxide enters into the following reactions:
1. neutralization with acids, acid oxides and amphoteric compounds. The result of this reaction is the formation of water and s alt or a hydroxocomplex - in the case of interaction with amphoteric bases and oxides;
2. exchange with s alts;
3. with metals that are up to hydrogen in the Beketov series and have a low electrochemical potential;
4. with non-metals and halogens;
4. hydrolysis with esters;
5. saponification with fats (soap and glycerin are formed);
6. interactions with alcohols (alcoholates are formed).
Also, in molten form, caustic soda can destroy porcelain and glass, and when oxygen is present, it can destroy a noble metal (platinum).
Sodium hydroxide can be obtained in the following ways:
- electrolysis of an aqueous solution of NaCl (diaphragm and membrane method),
- chemical (lime and ferrite method).
In recent years, methods based onelectrolysis, because they are more profitable.
Caustic soda is very popular and is used in many industries - cosmetics, pulp and paper, chemical, textile, food. It is used as an additive E-524, for decontamination of premises and in the production of biodiesel fuel.
Thus, sodium hydroxide is an alkali that has found wide application in various branches of human economic activity due to its reactive nature.
