With a chemical compound called caustic soda, a person meets daily. Sodium hydroxide, the chemical formula of which is designated NaOH, belongs to the category of caustic and strong alkalis, dangerous for the skin and mucous membranes. At the same time, it is actively used by the food industry, cosmetology, and pharmaceuticals. No personal hygiene product is complete without the addition of this compound. The chemical properties of the substance made it the most popular among acidity regulators and mediums to maintain consistency.
What is sodium hydroxide
This compound is caustic alkali, which is used not only in food, pharmaceutical and cosmetic spheres, but also in the chemical industry. Sodium hydroxide, or caustic soda, is available in the form of slightly slippery hard granules of yellowish or white color. With a strong concentration, NaOH corrodes organic compounds, so it can cause burns. Used as a food supplement E524, necessary to maintain the consistency of products.
Formula
The substance has the chemical formula NaOH.The compound interacts with various substances of any aggregate states, neutralizing them, with acids, forming salt and water. Reaction with atmospheric oxides and hydroxides makes it possible to obtain tetrahydroxocincate or alkali. Caustic soda is used to precipitate metals. For example, when reacting with aluminum sulfate, its hydroxide is formed. The sediment does not dissolve and there is no excessive alkali production. This is important when cleaning water from small suspensions.
Properties
The compound dissolves in water. Technical Sodium Hydroxide is an aqueous solution of sodium hydroxide in an alkali-resistant sealed container. When interacting with water, the caustic releases a large amount of heat. The substance has the following properties:
- during pre-melting destroys glass, porcelain;
- interaction with ammonia causes a fire hazard situation;
- boils at 1390 ° C, melts if the temperature reaches 318 ° C;
- does not dissolve in esters, acetone;
- is very hygroscopic( absorbs water vapor from the air), so sodium alkali should be stored in a dry place and hermetically sealed;
- is soluble in methanol, glycerol, ethanol;
- rapidly interacts with metals - tin, aluminum hydroxide, lead, zinc, forms hydrogen - an explosive combustible poison;
- absorbs carbon dioxide from the air.
Preparation of
Caustic soda is found in of brucite mineral .The second largest deposit is concentrated in Russia. Hydroxide, thanks to the research of Nikola Leblan, carried out in 1787, is obtained by the method of synthesis from sodium chloride. Later, the required method of production became electrolysis. Since 1882, scientists have developed a ferrite method of obtaining hydroxide in the laboratory with the aid of calcined soda. Electrochemical method is now the most popular: sodium ions form its solution of caustic mercury - amalgam, which is dissolved by water.
Application of sodium hydroxide
No more common alkali than caustic soda. Annually, about 57 million tons are consumed. Corrosive sodium is used in the preparation of medicines, phenol, organic dyes, glycerin .Another area of application is the disinfection of the room due to the ability of the chemical compound to neutralize substances harmful to humans that are in the air. More hydroxides are widely used to maintain the form of products( food industry).
In the industry
Sodium hydroxide belongs to a strong base for chemical reactions and is actively used by different industries due to its properties :
- Pulp industry - to eliminate sulphate in the composition of wood fibers for softening( delignification).This is necessary for the production of cardboard, paper, artificial fibers.
- Chemical industry - used for the production of oils, neutralization of acidic substances, in the etching of aluminum, the production of pure metals.
- Sodium hydroxide is used to produce biodiesel fuel based on vegetable oils, resulting in the formation of glycerin.
- The compound is washed by molds of automobile tires.
- In civil defense, it is common when neutralizing hazardous substances in the air, degassing.
- A tool is used for the illegal production of drugs such as methamphetamines.
Food supplement
Caustic soda purifies vegetables and fruits from the skin. The substance is used to impart a caramel color. As food additive E524( class of acidity regulators, anti-caking agents along with sodium carbonate) is used in the manufacture of cocoa, ice cream, butter, margarine, chocolate, soft drinks. Olives and olives soften, get black.
Food products - bagels and German pretzels( brezels) - are processed with a caustic solution for crispy crust. In the Scandinavian cuisine there is a fish dish - lutefisk .The cooking technology includes soaking for 5-6 days of dried cod in a hydroxide solution until a gelatinous consistency is obtained. In the food industry, soda helps to refine vegetable oil.
In the production of detergents
The ability of the interaction of fats with caustic has been noticed for a long time. Since the VII century Arabs have mastered the production of solid soap with the help of caustic soda and aromatic oils. This technology has remained the same. Caustic soda is added to shampoos, detergents, personal care products. Cosmetic industry uses Na hydroxide to get soap against fats, liquid for removing varnish, creams.
In household
The main way of use is gel-like hydroxide or its granules. It is part of the means for eliminating the clogs of sewerage, heating systems. The mud dissolves, disaggregates and passes on through the pipe. stainless steel products are cleaned of oil substances with caustic soda, heated to 50-60 ° C with the addition of potassium hydroxide. Cosmetology uses a gel based on it to soften the horny skin, papillomas, warts.
Sodium hydroxide in medicine
The compound is added to medicines against increased acidity of the stomach, for the laxative effect of strong action. Such a drug results in an increase in intestinal motility .The use of the substance restores the acid-base balance. It is used in medicine to achieve a soothing effect, suitable for purifying water from impurities. Due to sodium chloride, the osmotic pressure indicators of blood plasma remain constant. Do not confuse it with baking soda, salt.
Harmful sodium hydroxide
The substance is classified as the second hazard class. Due to the ability of hydroxides to corrode organic compounds, caustic application should be carried out in compliance with all precautions. When alkali falls on the mucous membranes and the skin, it causes severe burns, and interaction with the eyes leads to atrophy of the optic nerve. To neutralize the hydroxide on the skin, a weak vinegar solution and a large amount of running water are used.