Industrial Grade 99% Potassium sodium tartrate tetrahydrate 6381-59-5

 What is Potassium sodium tartrate tetrahydrate?

Potassium sodium tartrate tetrahydrate or sodium tartrate potassium or Rochelle salt or Rochelle salt is a complex salt of sodium tartrate and potassium tartrate. It was one of the first crystals found to have piezoelectric effects. Its chemical formula is often expressed as:

KNaC4H4O6.4H2O (CAS No.: 6381-59-5 Molecular Weight: approx. 282.22 Anhydrous: CAS No.: 304-59-6

At room temperature it is a colorless to bluish-white orthorhombic crystal, or a white crystalline powder. It is salty and cool in taste, with a density of about 1.79 g/cm 3 and a melting point of about 70-80℃. It loses 3 molecules of water of crystallization at 100. It loses all its water of crystallization at 130-140. It decomposes at 220. Sodium potassium tartrate is freely soluble in water (about 1.05g/ml at 20℃), almost insoluble in ethanol and the aqueous solution is neutral. It is frequently made commercially as a by-product from the wine industry.

In terms of molecular makeup, sodium potassium tartrate consists of tartrate, potassium and sodium ions. Two hydroxyl groups (-OH) in the molecule give it complexing and reducing abilities. In food, it is a safe acidity regulator (E337) for regulation of acidity and stabilization of texture. In chemistry, it is capable of reducing copper ions, and is a classic component of Fehling's reagent.

Sodium potassium tartrate is chemically stable, non-toxic and has reducing properties (it can reduce copper ion in silver ammonia solution and Fehling’s reagent). It is stable to air, and its aqueous solution is neutral. Store in a tightly sealed, dry container.

Non-industrial grade sodium potassium tartrate refers to food and scientific research products, mainly including food grade and reagent grade. The following indicators are more relevant for non-industrial grade products than for industrial grade products:

Control of Purity and Impurity

To ensure safe and precise use, food grade reagents and reagent grade reagents must possess high content of main components and strict control of impurities.

Limits on heavy metals (lead, arsenic, etc.)

Food has strict limits on harmful impurities such as heavy metals, which are important safety indicators.

Water and Crystallization water

The form and water of crystallization content of tetrahydrates affect the accuracy of measurement and storage stability, must be within specifications.

Free acid & free base

Free residual acids or alkalis can affect the stability of the formulation and the quality of the product and have to be tightly controlled.

 What are the uses of Potassium sodium tartrate tetrahydrate?

1. Food additives (food grade, core application)

Sodium potassium tartrate (E337) is a legal food additive used as an acidity regulator and stabilizer in jams, beverages and gels to regulate acidity and stabilize texture. It is also used as acidic salt component of leavening agents The amount used should be in compliance with the standards for the use of food additives.

2. Electroplating complexing agents (primary application)

Sodium potassium tartrate is an important complexing agent in cyanide free electroplating systems. It forms stable complexes with metal ions such as copper, zinc and nickel. It is used in cyanide free copper plating, gold plating and zinc-nickel alloy electroplating. It is an important raw material for green electroplating, and it helps to control the growth of the grain and the quality of the coating.

3. Laboratory and scientific research uses (reagent grade)

Sodium potassium tartrate is an important reagent used in analytical chemistry. It is used for the preparation of Fehling and Benedict’s solution for detection of reducing sugars. It is also used as a complexing masking agent and as a reagent for metal ion analysis. It can also be used in scientific research and teaching of piezoelectric crystal.

4. Chemical reagents and detection of reducing sugars

Sodium potassium tartrate is an important component of Fehling's reagent and Benedict's solution, both of which are used for qualitative and quantitative detection of reducing sugars. It is also a complexing masking agent for quantitative analysis of uric acid and sugars and an important reagent in analytical chemistry laboratories.

5. Mirror manufacturing and silver plating industry

Sodium potassium tartrate is used as a reducing agent in the mirror-making industry and in the thermos flask (insulated flask) industry. In the silver mirror reaction it reduces silver ammonia solution to give a layer of silver on the glass surface. It is used in the manufacture of mirrors, thermos flask linings and reflectors.

6. Materials of piezoelectric elements

Single crystals of sodium potassium tartrate are the earliest piezoelectric materials in history. They possess ferroelectric properties and can be used to make piezoelectric elements in the temperature range of -18~22.5℃. They have been used for a long time in electroacoustic devices like loudspeakers, microphones, crystal microphones and phonograph cartridges.

7. Experiments of Science Education and Popularization

( 1 ) Fehling 's reagent for potassium sodium tartrate to detect reducing sugars and silver mirror reaction are classic experiments in middle school and university chemistry classes . They are of great help for students to intuitively understand reduction reactions, and are widely used experimental materials in chemistry teaching.

( 2 ) Potassium sodium tartrate can be used in home chemistry experiments and popular science activities, such as silver mirror reaction and sugar detection experiments, so that enthusiasts can experience the fun of chemistry within a safe range.

8. Other uses

With the advancement of food and testing technologies, the scope of non-industrial grade sodium potassium tartrate is expanding in the areas such as custom synthesis, supply of standard reagents, and analytical testing services.

It should be pointed out that non-industrial grade specifications do not mean "risk-free" . Sodium potassium tartrate is generally safe but food-grade products must be used according to standard limits . Reagent-grade products should be used according to laboratory safety regulations to avoid inhaling dust when used in experiments .

Summary

Potassium sodium tartrate tetrahydrate ( Rochelle salt ) is a colorless to bluish-white orthorhombic crystal. It is one of the first crystals found to be piezoelectric and has many properties including complexation, reduction, and safety. We encounter it indirectly all the time in electroplated hardware and electronic products, food (E337), mirrors and thermoses, chemical testing and audio equipment. In non-industrial applications food-grade and reagent-grade potassium sodium tartrate are widely used in food acidity regulation and stabilization, Fehling's and Benedict's solutions for reducing sugar detection, silver mirror reaction teaching experiments and piezoelectric crystal research. It is an important salt of tartaric acid that links “daily use” with “food and scientific research.”