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| Synonyms:Potassium salt of hydriodic acid Iodide of potash Potassium monoiodide Molecular Formula:KI Molecular Weight: 166 HS Code: 2827600000 Grade: Industrial grade ，Food Grade，98% 99% Hazard Class:General Cargo | |||||||||
7681-11-0
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7681-11-0
Potassium iodide, also known as potassium iodide, is the iodide of potassium and one of the most widely used inorganic salts of iodine in chemical and analytical fields. Its chemical formula is usually written as:
KI (CAS No.: 7681-11-0, EINECS No.: 231-659-4, molecular weight approximately 166.00, iodine content approximately 76.45%)
Potassium iodide is a colorless or white crystalline powder at room temperature, odorless, with a salty and bitter taste. It has a melting point of approximately 681℃, a boiling point of approximately 1330℃, and a relative density of approximately 3.12. It is extremely soluble in water (approximately 1280-1440 g/L), and its aqueous solution is neutral or slightly alkaline. It is slightly soluble in ethanol. Potassium iodide is hygroscopic and will precipitate free iodine and turn yellow upon prolonged exposure to light or oxidizing agents.
From a molecular structure perspective, potassium iodide is a typical ionic crystal, composed of potassium ions (K+) and iodide ions (I-) bonded together by ionic bonds. Iodine atoms have a large atomic radius and low electronegativity, and iodide ions are easily oxidized to elemental iodine (I-→I2). Therefore, potassium iodide is not only a stable iodine source but also has mild reducing properties and can dissolve elemental iodine to generate triiodide ions (I3-)—a property that makes it a core substance for iodometric titration analysis, iodine tincture preparation, and organic synthesis catalysis.
Chemically, potassium iodide is hygroscopic in the air. When exposed to light, acidic environments, and oxidizing agents, iodide ions are easily oxidized, releasing free iodine and turning yellow. Therefore, industrial-grade products must also be stored in a sealed, light-proof, and moisture-proof manner, and should not be mixed with oxidizing agents during use and transportation.
Industrial-grade potassium iodide refers to products used in industrial applications such as chemical processing, testing, animal feed, and surface treatment, with a purity generally above 98%. Compared to food-grade, industrial-grade products place greater emphasis on the following indicators:
Content (purity of potassium iodide)
Industrial grade generally requires a main content of 98% or higher (reagent grade can reach 99% or higher), and the content determines the accuracy and efficiency of catalysis, reaction and preparation.
Moisture
Potassium iodide is hygroscopic and prone to clumping, so moisture content must be strictly controlled to ensure storage stability and measurement accuracy.
Free iodine and iodate
Oxidation products, such as free iodine and iodate, can affect product color, reaction stability, and downstream quality, and are key quality control indicators.
Water-insoluble matter
The aqueous solution must be clear and transparent, free of mechanical impurities and insoluble matter, to ensure the cleanliness of downstream solution preparation and reaction systems.
Heavy metal limits
Industrial-grade products still have limits on the content of heavy metals such as lead and arsenic.
Industrial-grade potassium iodide, with its stable iodine source, mild reducing properties, and good solubility, is widely used in the chemical, testing, and materials fields.
Potassium iodide is a catalyst and auxiliary agent for a variety of organic synthesis reactions, used in esterification, carbonylation, alkylation and other reaction systems. It is also an important catalyst for the synthesis of carbonate compounds, serving the fine chemical and new materials industries.
Potassium iodide is a fundamental reagent in iodometric analysis (iodine titration), used to determine vitamin C, sulfites, dissolved oxygen, and various redox substances. It is also a core raw material for preparing iodine standard solutions and starch-potassium iodide test paper, and is widely used in analytical laboratories.
Potassium iodide is used as a solubilizer for tincture of iodine and as a stabilizer for iodine-based disinfectant products.
Potassium iodide is used as an iodine additive in livestock, poultry, and aquatic feed to provide animals with essential iodine nutrition, maintain thyroid function and normal growth, and is a commonly used iodine source in feed premixes.
Potassium iodide is an auxiliary component of silver halide photosensitive emulsions, used in the preparation of traditional photosensitive materials such as film and photographic paper, and continues to be used in the fields of image archive restoration and special photosensitive materials.
Potassium iodide is used as a complexing agent in cyanide-free gold plating processes. It forms stable complexes with gold ions and is used for gold plating of jewelry, electronic connectors and precision devices. It is an important auxiliary agent in green electroplating processes.
With the development of green chemical and electronics industries, the application of industrial-grade potassium iodide continues to expand, including as an iodine source in dye and pesticide synthesis, as an auxiliary reagent in water treatment and oilfield chemistry, and in the recovery and reprocessing of iodine.
It should be noted that industrial-grade specifications do not equate to "risk-free": although potassium iodide has low toxicity, industrial-grade products may contain process impurities and are strictly prohibited from being ingested; dust inhalation and skin contact should be avoided, the place of use should be well-ventilated, and it should be stored away from oxidizers.
Potassium iodide (KI, CAS No. 7681-11-0) is a colorless or white crystalline powder, highly soluble in water and a classic iodine source compound with about 76.45% iodine. It has a stable iodine supply ability and mild reducing property. In daily life, we meet him indirectly through the feed and livestock industry chain, testing laboratories, gold-plated products, chemical industrial products and imaging industry. Industrial grade potassium iodide with purity higher than 98% is widely used in organic production catalysts, iodine analysis reagents, feed additives, photosensitive materials, cyanide-free gold plating complexing agents, fine chemical synthesis and other industries, which is an important inorganic salt connecting "iodine chemistry" and "chemical engineering, testing and materials science".
