- organic compound, crystalline hydrate of double (potassium and sodium) salts of tartaric acid. This substance was named after a French pharmacist who made it from wine-making waste in the 17th century and used it as a laxative with shognet salt. Formula - KNaC4H4O6.4H2O. Segnet's salt is the traditional name. Chemists use: potassium-sodium tartrate 4-water or potassium-sodium tartrate tetrahydrate.

Rochelle's salt is obtained artificially by chemical reaction of tartaric acid with potassium carbonate (carbonate) and sodium.

Properties

Under normal conditions, it is a crystalline substance, salty in taste, with a cooling effect. Crystals can be colorless, white, bluish.

They have a complex structure and shape, do not have a center of symmetry, and are dodecahedral. They dissolve well in water, do not dissolve in alcohol. The reagent begins to decompose already at temperatures above +56 ° C. With strong heating, it first loses crystallization water, then decomposes into potassium-sodium carbonate, water and carbon monoxide. Possesses ferroelectric and piezoelectric properties. Segnet's salt is non-toxic, does not burn, fire and explosion proof.

Rochelle salt crystals were the first to have late XIX centuries have discovered special electrical properties - spontaneous polarization in a certain temperature range. It turned out that the polarization of the crystal can be controlled by a strong magnetic field... After that, the entire class of substances with similar properties began to be called ferroelectrics. To date, this class includes more than seven hundred substances.

Crystals of sodium-potassium tartrate aroused even greater interest when Pierre and Jean Curie discovered a piezoelectric effect in them, and three thousand times stronger than that of quartz crystals. The piezoelectric effect is the occurrence of electrical discharges during mechanical action on solid... On its basis, before the Second World War, many different electronic devices: ultrasonic locators, loudspeakers, hearing aids, medical probes, telephones, microphones and many others. Most were originally designed for wafers cut from quartz crystals, but these were very expensive and required sophisticated diamond sawing equipment. Rochelle salt crystals were much cheaper and were cut simply with a damp thread. Unfortunately, they were fragile, unstable to temperature extremes and high humidity. In the end, these shortcomings were overcome by placing the plates in waterproof shells. Mass production of reagent-based electronic piezoelectric devices began. As the famous academician Aleksandrov said: "Segnet's salt turned out to be a gold mine for physicists."

The production of devices and apparatus based on the piezoelectric effect stimulated the creation of a new branch of industry - the growing of large ferroelectric crystals. In the Soviet Union, during the war, it was possible to reduce the period of growing one and a half to two kilogram crystals of Rochelle salt from the initial six months to 8-9 days. The army needed them so much that they were grown even in besieged Leningrad. In total, 54 tons of crystals were grown during the war. They were used in the manufacture of laryngophones (a device like a microphone that uses skin vibrations on the larynx) for tankers and pilots, underwater locating and communication devices, piezoelectric fuses, loudspeakers from which the population received all the news and information, etc.

Currently, Rochelle salt plates are almost never used as piezoelectrics. They were replaced by more durable crystals such as barium titanate.

Application

In the chemical industry - in organic syntheses for the destruction of emulsions in aqueous solutions; v analytical chemistry for the preparation of buffer and standard solutions; is a part of reagents for aldehydes and ketones.
... In the food industry, as an antioxidant and baking powder, an emulsifier in cheese making; is a part of baking powders.
... For silvering mirrors.
... In radio engineering and electronics.
... For cleaning gilded bronze (Rochelle salt does not interact with copper oxides, therefore only copper salts and hydrates are removed).
... For the preparation of electrolytes for electroplating.
... In medicine, biology, analytical chemistry, they are used to prepare solutions for the detection of sugars and proteins.
... For the production of medicines, including laxatives in pharmacology.
... As a plant growth stimulant in agriculture.

Potassium sodium tartrate GOST 5845-79

KNaC 4 H 4 O 6 4H 2 O

Segnet's salt- tetrahydrate of double sodium-potassium salt of tartaric acid ( sodium potassium tartrate). Named for the French pharmacist Pierre Seignet (fr. Pierre seignette), 1660-1719 (other sources indicate the name of the pharmacist Elie Seigner (1632-1698), as well as the years of obtaining salt - 1672 and 1675).

Chemical properties and applications

Since sodium potassium tartrate is a tartaric acid salt, several optical isomers correspond to it. Only L - (+) - tartaric acid is found in nature

The tetrahydrate is soluble in water well (54 g / 100 g) at 15 ° C, at 30 ° C 1390 g / l), moreover, the salt is hygroscopic. However, the salt as such is obviously poorly soluble, since it precipitates during the preparation reaction.

Sodium potassium tartrate is a component of Fehling's liquid, in which it is used to detect sugars. Also Rochelle salt is used in silvering mirrors according to the Henrikhson method. In addition, this salt is used in organic synthesis as a demulsifier in aqueous solutions, usually in reactions using aluminum hydride. Finally, the solution for the determination of proteins by the biuret method also contains potassium sodium tartrate.

In the laboratory, this salt is obtained by precipitation in a fine-crystalline form from a hot solution of acidic potassium tartrate by adding a stoichiometric amount of Na 2 CO 3.

Segnet's salt "chda" (potassium-sodium tartrate, tartrate, potassium-sodium tartrate) is a tetrahydrate of sodium-potassium double salt of tartaric acid in the form of colorless or white hygroscopic crystals of the rhombic system. We offer to buy this product in our company.

The material is obtained industrially by the interaction of tartaric acid with sodium and potassium carbonate salts. When manufacturing in this way, it becomes possible to increase the size of the crystals, if necessary. In laboratory practice, the reagent is synthesized by precipitation from a heated solution of acidic potassium tartrate in fine-crystalline form by adding stoichiometric amounts of sodium carbonate.

Segnet's salt, the price per kg of which we have is low, is characterized by weak alkalinity and increased hygroscopicity. It mixes well with water, but does not dissolve in ethyl alcohol. When heated to 55.6 ° C, the reagent begins to decompose. It has piezoelectric properties, which led to its demand in technology: in handsets, pickups for electrophones, hearing aids, microphones and other similar devices.

Application area

Potassium-sodium tartrate, the price of which is favorable in our company, is used as a demulsifier in aqueous solutions, as well as when carrying out reactions using aluminum hydride in organic synthesis processes. It also applies:

• as part of Feeling liquid for the detection of sugars;
• for the determination of proteins in solutions by the biuret method;
• as a reducing agent for silvering mirrors according to the Henrikhson method;
• to increase the life of cigarette paper in the manufacture of cigarettes;
• as an emulsifier in cheese making, an antioxidant additive and a baking powder E337, as part of baking powders in Food Industry;
• as a reducer in the printing industry;
• to increase the time interval before the start of plaster hardening in construction;
• as a component of Seydlitz powder in the production of laxatives, as well as in the production of effervescent and instant preparations;
• to increase the saturation of the solution with anodes, create a good uniform surface and ensure the possibility of working at high concentrations in the composition of electroplating baths;
• when cleaning bronze with gilding, since the reagent does not react with copper oxides;
• as a plant growth stimulator in agriculture;
• as a desalting agent in the chemical industry.

This material is sold in our organization at an affordable cost, you can buy it in packs of 25 kg.

Precautionary measures

The product is non-toxic, non-flammable, non-flammable and does not form explosive mixtures with air. According to the degree of impact on the body, it belongs to the group of substances of the third hazard class. When working with it, you must use protective equipment: plastic goggles, thick rubber gloves, industrial respirator, special shoes and clothing. This material is sold in rubles. in LLC "AQUAKHIM".

Storage features

The reagent should be stored in unopened containers in dry, ventilated storage areas. Expiration date - 36 months from the date of manufacture.

Segnet's salt: where is it sold with delivery in the Russian Federation?

We sell chemical products at affordable prices. If you want to buy quality goods with shipment all over Russia, we suggest that you familiarize yourself with the full price list of our online store on the main page of this site. To place an order, just click on the green button above and enter your contact details in the field that opens. Our employee will call you back during working hours.

Potassium sodium tartrate- acidity regulator, acidifier, antioxidant synergist, salt substitute, emulsifying salt, color stabilizer.

Potassium-sodium tartrate physical and chemical properties

Colorless transparent crystals, in the mass - white, have a salty, cooling taste on the tongue. Let's dissolve in water (1 g in 1 ml); insoluble in ethanol, oils, fats.

Potassium Sodium Tartrate Natural Source

In many types of vegetables and fruits in the form of tartaric acid.

Obtaining potassium sodium tartrate

The interaction of L-tartaric acid with caustic soda and caustic potassium or sodium and potassium carbonates. Impurities: malates, other tartrates, oxalates. According to the tartaric acid content.

Daily intake of sodium potassium tartrate

Chipboard 30 mg / kg body weight per day in terms of L (+) - tartaric acid. There are no dangers for GN-98.

Reference in standards and application in the food industry E-337

E-337 approved as a regulator of acidity of the following food products: soups, broths in an amount of up to 250 mg / kg of the finished product; jams, preserves, jellies, citrus marmalades up to 3 g / kg individually or in combination with TARTARIC ACID, FUMARIC ACID and its salts to maintain a pH between 2.8 and 3.5; margarines GMP. In the Russian Federation, canned fruits and vegetables are allowed in quantities according to TI (clause 3.1.18 SanPiN 2.3.2.1293-03); in wines, drinks, food concentrates and other products, in bakery and flour confectionery products in an amount according to TI individually or in combination with tartaric acid and tartrates (p. 3.2.3,3.6.52 SanPiN 2.3.2.1293-03). Tartrates form stable complexes with iron and heavy metals and thus act as antioxidant synergists. They are sometimes used as melting salts in the production of processed cheese. The slow release of potassium and calcium from their salts regulates the rate of gelling of carrageenan, alginate and pectin gels. Sodium potassium tartrate can be used as a salt substitute.

Other uses of sodium potassium tartrate:

E-337 used in the manufacture of pharmaceuticals, as well as for silvering mirrors, as a mouthwash, laxative