月: 2023年1月

What Is Cerium Chloride?

Cerium(III) chloride is an inorganic compound with the chemical formula CeCl₃.

It is sometimes referred to as cerium(III) chloride to indicate its valence. In addition to anhydride, heptahydrate is also known, with CAS numbers 7790-86-5 (anhydride) and 18618-55-8 (heptahydrate), respectively. The anhydride readily forms hydrates due to its high hygroscopicity.

Both cerium chloride anhydrate and cerium chloride heptahydrate are classified as skin corrosive/irritant and eye irritant under the GHS classification. The legal classification of cerium chloride, both anhydrous and heptahydrate, is not applicable under the Industrial Safety and Health Law, the Labor Standards Law, the PRTR Law, and the Poisonous and Deleterious Substances Control Law.

Uses of Cerium Chloride

Cerium chloride is used as a raw material for synthesizing other cerium compounds and as a Lewis acid in organic synthesis. Cerium trifluoromethanesulfonate (Ce(OTf)₃), used as a Lewis acid in the Friedel-Crafts acylation reaction, is a useful starting material for cerium chloride.

Cerium chloride is also used as a catalyst for the polymerization of olefins, in the Rouxier reduction of α,β-unsaturated carbonyl compounds, in the alkylation of ketones, and as an additive in Grignard reactions.

Properties of Cerium Chloride

1. Cerium Chloride (Anhydrous)

Cerium chloride anhydride has a molecular weight of 246.48, a melting point of 817°C, and a boiling point of 1,727°C. It is a white to pale yellow crystal or powder in appearance at room temperature. It has a density of 3.97 g/mL and solubility in water of 100 g/100 mL. It is soluble in alcohol as well as water.

2. Basic Information on Cerium Chloride (Heptahydrate)

Cerium chloride heptahydrate has a molecular weight of 372.58, a melting point of 848°C, and a white to light yellow crystalline powder or powder in appearance at room temperature. It has a density of 3.97 g/mL and is extremely soluble in water and ethanol.

Types of Cerium Chloride

Cerium chloride is sold as a reagent product for research and development and as a rare earth compound for industrial use.

1. Reagent Products for Research and Development

Most of the products sold as R&D reagent products are cerium chloride heptahydrate. However, there are a few manufacturers that offer anhydride. The product is generally available in 10g, 25g, 100g, and 500g capacities, which are easy to handle in the laboratory. Heptahydrate is treated as a stable reagent product that can be stored at room temperature.

2. Rare Earth Compounds for Industrial Use

As for industrial products, stable heptahydrate is sold. The expected use for this product is as a raw material for cerium compounds and catalysts. In addition to pure substances, they are also sold in aqueous solution. As for the capacity, etc., it is necessary to inquire individually as it differs from manufacturer to manufacturer.

Other Information on Cerium Chloride

1. Synthesis of Cerium Chloride

Cerium chloride can be synthesized from cerium metal and hydrogen chloride. Another known method is to obtain it by heating trivalent cerium oxide, hydroxide, or carbonate mixed with ammonium chloride. Heating the hydrate yields an anhydride, but rapid heating of the hydrate alone may cause a small amount of hydrolysis.

To obtain pure anhydride, the hydrate can be heated slowly to 400 °C with four to six equivalents of ammonium chloride under a high vacuum, or with excess thionyl chloride for about three hours. Or, more simply, anhydride can be obtained by heating heptahydrate gradually to 140 °C in a vacuum over many hours, but it may contain some hydrolysis products. However, even this degree of purity can be used with organolithium and Grignard reagents.

2. Chemical Reaction of Cerium Chloride

Cerium chloride is not only used as a raw material for other cerium compounds but can also be used by itself as a Lewis acid in organic synthesis. For example, cerium chloride heptahydrate is used together with sodium borohydride NaBH4 in the Rouxier reduction of α,β-unsaturated carbonyl compounds. Otherwise, it prevents the formation of enolates in the alkylation of ketones.

What Is Cesium Chloride?

Cesium chloride is an inorganic compound with the chemical formula CsCl.

In the laboratory, cesium chloride is obtained by treating cesium hydroxide, cesium carbonate, cesium bicarbonate, or cesium sulfide with hydrochloric acid.

Cesium chloride is not toxic to humans or animals; none of the GHS classifications apply to it. It is not regulated by the Industrial Safety and Health Law, the Labor Standards Law, the PRTR Law, or the Poisonous and Deleterious Substances Control Law.

Uses of Cesium Chloride

Examples of applications of cesium chloride include phototubes, photosensitive deposition films, phosphors, catalysts, optical fibers, chlorinating agents, and reagents for density gradient centrifuges. It can be used as a cesium ion source in the synthesis of other cesium compounds.

DNA separation reagents and vacuum tube materials are particularly unique uses of cesium chloride. As a radioactive isotope, cesium chloride is also used in scintigraphy. Scintigraphy is a diagnostic technique that detects and visualizes radiation from the administration of radioactive isotopes in the body.

Properties of Cesium Chloride

Cesium chloride has a melting point of 645°C and a boiling point of 1,295°C. It is a white crystal or crystalline powder.

Cesium chloride is deliquescent. When dissolved in water, it dissociates completely and Cs⁺ is solvated by a dilute solution.

Cesium chloride can be converted to cesium sulfate by heating it in concentrated sulfuric acid or with cesium hydrogen sulfate at 550-700°C. Cesium chloride forms various complex salts with other chlorides. Examples include 2CsCl・BaCl₂, CsCl-2CuCl, 2CsCl-CuCl₂, and CsCl-LiCl.

Structure of Cesium Chloride

Cesium chloride has a formula weight of 168.36 g/mol and a density of 3.99 g/cm³.

The solid is an ionic crystal, a simple cubic lattice composed of chloride ions (Cl⁻) and cesium ions (Cs⁺). Each chloride ion is flanked by eight cesium ions; a salt crystal with a composition ratio of 1:1 takes on a cesium chloride-type structure when the radii of the two types of ions are approximately equal. The cesium chloride-type structure is one of the typical structures of ionic crystals. Besides cesium iodide and cesium bromide, other compounds known to form cesium chloride-type structures include copper-zinc and iron-rhodium 1:1 alloys.

Cesium chloride has a lattice constant of a = 0.411 nm and an interatomic distance Cs-Cl of 0.345 nm.

Other Information on Cesium Chloride

1. Cesium Chloride in Nature

Cesium chloride occurs naturally as an impurity in the halogenated minerals carnallite (KMgCl₃・6H₂O containing up to 0.002% CsCl), potash rock salt (KCl), kainite (MgSO₄・KCl・3H₂O), and mineral water. For example, the water in the spa in Bad Durkheim used for cesium separation contained about 0.17 mg/L of cesium chloride.

2. Method of Synthesizing Cesium Chloride

Industrially, cesium chloride can be purified by dissolving cesium carbonate in hydrochloric acid and recrystallizing it. Cesium chloride is produced from Pollucite, and when the extract is treated with antimony chloride, iodine monochloride, or cerium(IV) chloride, it is formed as an insoluble double salt. Hydrogen sulfide yields cesium chloride. Recrystallization of pyrolyzed Cs[ICl₂] or Cs[ICl₄] can produce high-purity cesium chloride.

3. Hazards of Cesium Chloride

The median lethal dose (LD₅₀) of cesium chloride in mice is 2,300 mg per kg body weight by oral administration and 910 mg/kg by intravenous injection. Cesium chloride partially displaces potassium, thus decreasing potassium levels in the body. Large doses of cesium chloride can cause potassium imbalance, resulting in hypokalemia, arrhythmia, and acute cardiac arrest.

What Is Tin Chloride?

Tin chloride is a tin chloride that exists in two forms: tin dichloride with an oxidation number of 2 and tin tetrachloride with an oxidation number of 4.

It is a very strong reducing agent, and when oxidized in air, it changes to tin oxide. Tin dichloride is a colorless crystal, while tin tetrachloride is a colorless liquid. Besides being widely used in industrial applications, tin tetrachloride is one of the most important raw materials in the manufacture of tin.

Both tin dichloride and tin tetrachloride are designated as “deleterious substances” under the Poisonous and Deleterious Substances Control Law. Since they are toxic to the human body, care must be taken when handling them.

Uses of Tin Chloride

1. Tin Dichloride

An acidic aqueous solution of tin dichloride has strong reducing properties. Taking advantage of this property, tin dichloride is used as a reducing agent and reaction catalyst for water-soluble organic compounds and as an analytical reagent in the field of analytical chemistry.

Other applications that take advantage of its strong reducing properties include ink erasing, silver plating of mirrors, leather tanning agents, and as a raw material for mordant solutions used to stop color during dyeing.

2. Tin Tetrachloride

Tin tetrachloride is used in industrial applications as a raw material for the synthesis of organotin compounds, as a mordant, condensing agent, reaction catalyst, and conductive paint.

Properties of Tin Chloride

1. Tin Dichloride

Tin dichloride is represented by the chemical formula SnCl₂ and has a molecular weight of 189.62. Its CAS number is 7772-99-8.

Tin dichloride has a melting point of 246°C, a boiling point, an initial distillation point, and a boiling range of 623°C, and no information on its flash point or explosive range. It is very soluble in water, with a solubility of 900 g/kg (at 20°C).

It decomposes when heated, producing toxic and corrosive gases. It is a strong reducing agent and reacts with oxidants (nitrates, peroxides, bases, etc.), so care should be taken when handling it.

2. Tin Tetrachloride

Tin tetrachloride has the chemical formula SnCl₄, a molecular weight of 260.52, and CAS number 7646-78-8.

Tin tetrachloride has a melting point of -33 °C, a boiling point of 114.1 °C, a spontaneous combustion temperature above 654 °C, and no information on flash point or explosive range.

It is chemically stable under standard atmospheric conditions but reacts with aluminum, metals, oxides, air, and moisture. In case of fire, hydrogen chloride gas, tin oxides, and other toxic gases may be generated.

Other Information on Tin Chloride

1. How Tin Chloride Is Produced

Tin dichloride is produced by dissolving metallic tin in hydrochloric acid to form a dihydrate. The dihydrate is then reacted with acetic anhydride to form anhydrous tin dichloride.

Tin tetrachloride is generally produced by directly reacting metallic tin with chlorine gas, followed by distillation to produce tin tetrachloride.

2. Safety of Tin Chloride

Tin dichloride may cause respiratory irritation, and there is a risk of liver, kidney, and blood system damage due to long-term or repeated exposure. Tin dichloride is highly toxic to aquatic organisms, so care should be taken when handling and disposing of it.

Tin tetrachloride poses a risk of serious skin and eye damage, as well as respiratory irritation, and may be life-threatening if inhaled. It is also harmful to aquatic organisms due to long-term persistent effects.

In case of fire, avoid stick discharge and extinguish with water spray, foam, powder extinguishing media, carbon dioxide, and dry sand. Firefighters should wear appropriate air respirators and chemical protective clothing when extinguishing fires due to the risk of irritant, corrosive, and toxic gases being generated.

3. Handling Methods

As with all tin dichloride and tin tetrachloride, appropriate protective gloves, protective clothing, protective glasses, and protective masks should be worn when working with tin dichloride and tin tetrachloride. Avoid eating, drinking, and smoking when handling, and wash skin after handling.

Tin dichloride should be handled in workplaces with local exhaust ventilation or total ventilation, and care should be taken not to inhale dust, vapor, or spray. Tin tetrachloride should be handled under inert gas because it reacts with air and moisture. Wearing filter-type respiratory protection is recommended.

4. Storage Methods

Tin dichloride should be stored in a well-ventilated area with the container tightly closed and locked. Tin tetrachloride should be stored in appropriate material containers, such as those with corrosion-resistant or corrosion-resistant linings. In addition, since it reacts with moisture and oxygen, it should be sealed with an inert gas and stored in a cool dry place.

What Is Potassium Chloride?

Potassium chloride is a compound of potassium and chlorine.

It is a colorless crystal or white crystalline powder. It is also known as potassium chloride, potassium chloride, or potassium chloride.

Potassium chloride can be industrially purified from natural ores such as potassium salt (Sylvite), carnallite, and silvinite. Potassium chloride can be produced by the continuous melting method or the flotation method, and highly purified potassium chloride is not deliquescent.

Uses of Potassium Chloride

Potassium chloride has a high safety profile and is approved for use as a food additive. Specifically, it can be used as a substitute for salt (sodium chloride) in many foods, including seasonings, low-sodium foods, and soft drinks. Supplements are also manufactured to provide potassium, an essential mineral.

In the medical field, it is also used as a potassium supplement (oral or intravenous solution) for hypokalemia. In agriculture, it can be used as a fertilizer. Furthermore, electrolyzed hypochlorite water, which is used to sterilize crops, is made by electrolyzing potassium chloride solution.

When potassium chloride is electrolyzed, potassium hydroxide is produced along with hydrogen and chlorine. Potassium hydroxide can be used as a raw material for soap and other chemical products, making it possible to use potassium chloride as a chemical raw material.

Potassium chloride is also used as a drilling fluid when drilling for natural gas or oil. It is called KCl polymer mud and was developed around 1980.

Properties of Potassium Chloride

The chemical properties of potassium chloride are similar to those of sodium chloride. It is easily soluble in water and endothermically soluble in polar solvents. It is virtually insoluble in ethanol and diethyl ether.

Its melting point is 776°C and its boiling point is 1,505°C. It tastes salty and has a distinctive bitter taste. It is nonflammable and less toxic. The Fire Service Law and the Poisonous and Deleterious Substances Control Law do not apply to it. However, care should be taken when storing it at high temperatures.

Structure of Potassium Chloride

Potassium chloride is a chloride of potassium, with the chemical formula KCl. In an aqueous solution, it is ionized into chloride ions (Cl^–) and potassium ions (K⁺). pH is approximately 7.

The crystal lattice has a sodium chloride-type structure. The coordination number is 6, the distance between potassium and chlorine (K-Cl) is 0.314 nm, and the lattice constant is a = 6.278Å. Its molar mass is 74.551 g/mol and its density is 1.987 g/cm³.

Other Information on Potassium Chloride

1. Manufacturing Process of Potassium Chloride

Potassium chloride is produced by the neutralization reaction of hydrochloric acid and potassium hydroxide. Industrially, the mineral product is refined. One method of purification uses solubility differences. The mixture is dissolved in water and crystallized continuously as the water evaporates. The disadvantage, however, is that it requires a lot of energy for heating and is expensive.

If you want to save more cost, the flotation beneficiation method is recommended. First, saturated brine is added to the mixture. Then, air is blown into the suspension to selectively attach potassium chloride crystals to the bubbles, and the bubbles are scooped out. Sodium chloride crystals precipitated at the bottom can also be recovered.

2. Naturally Occurring Potassium Chloride

Plants use potassium as a nutrient. Therefore, potassium chloride is found in algal salt produced by burning seaweed, and ash salt produced by burning inland plants. In addition to that, it is one of the constituents of bittern, which is produced when sea salt is made.

In nature, it is produced as potash ore. Besides precipitating from salt lakes and seawater trapped inland to form deposits, crystals are also obtained from volcanic fumaroles. The main production area in Japan is Chiba. Seawater contains about 0.08% potassium chloride. It can also be extracted from seaweeds, but Japan imports most of its potassium chloride.

What Is Aluminum Chloride?

Aluminum chloride, with the chemical formula AlCl₃, is either a white or light-yellow solid known for its strong deliquescence. It has a water solubility of 45.8 g/100 ml at 20°C and comes in anhydrous and hexahydrate forms. The anhydrous form can be produced by reacting aluminum with chlorine or hydrogen chloride gas, whereas polyaluminum chloride is synthesized from aluminum hydroxide and hydrochloric acid.

Uses of Aluminum Chloride

Aluminum chloride finds its primary applications in pharmaceuticals and water treatment as a coagulant. In medicine, it treats hyperhidrosis by causing inflammation and blocking sweat glands. As polyaluminum chloride, it aids in water, sewage, and industrial water treatment by settling out particulate matter and suspended solids due to its coagulation and precipitation properties.

Properties of Aluminum Chloride

1. Basic Properties

With a molecular weight of 133.34, a melting point of 190℃, and a specific gravity of 2.44, aluminum chloride reacts in water to produce aluminum hydroxide Al(OH)₃ and hydrogen chloride (HCl). Concentrating and heating its aqueous solution dehydrates the hexahydrate form to [Al(H₂O)₃]Cl₃, eventually leading to the formation of alumina Al₂O₃.

2. Lewis Acid Catalyst Properties

As a Lewis acid catalyst in organic chemistry, aluminum chloride facilitates alkylation and acylation in Friedel-Crafts reactions. During these reactions, AlCl₄^– forms, aiding in nucleophilic substitution by coordinating to an intramolecular electron pair. The amount of aluminum chloride impacts the reaction’s progress in alkylation, whereas in acylation, its efficacy decreases unless an equivalent or greater amount is used due to complex formation with the carbonyl oxygen of the formed aromatic acyl.

Types of Aluminum Chloride

Besides anhydrous aluminum chloride and its hexahydrate, polyaluminum chloride [Al(OH)_nCl_6-n]_m, where 1≤n≤5 and m≤10) exists. In water treatment, its high positive charge neutralizes the negatively charged surfaces, aggregating turbidity into flocs that precipitate.

Structure of Aluminum Chloride

1. Anhydrous Aluminum Chloride Structure

Anhydrous aluminum chloride features a crystal structure with one aluminum atom surrounded by six chlorine atoms in a distorted octahedral shape, forming a two-dimensional sheet layer. In liquid or gas form, it becomes a dimeric molecule, Al₂Cl₆, with a cyclic structure linking two Al atoms with two Cl atoms.

2. Aluminum Chloride Hexahydrate Structure

The structure of aluminum chloride hexahydrate, [Al(H₂O)₆]Cl₃ or AlCl₃・6H₂O, highlights a trivalent complex ion where six water molecules coordinate to the Al atom.

Other Information on Aluminum Chloride

Production Methods

The industrial process for anhydrous aluminum chloride involves introducing chlorine gas into molten aluminum. The resulting aluminum chloride gas sublimates and is then solidified in a cooler.

What Is Sulfur Hexafluoride?

Sulfur hexafluoride, with the chemical symbol SF₆, is a nonflammable, heat-resistant, non-corrosive gas known for its exceptional insulating properties and chemical stability. It persists in the atmosphere for around 3,200 years and significantly impacts global warming, being over 20,000 times more potent than CO₂. Its applications have grown despite its potential environmental impact, primarily due to human activities.

Uses of Sulfur Hexafluoride

Used extensively as an insulator in electrical equipment like circuit breakers and gas-insulated switchgear, sulfur hexafluoride also prevents oxidation in magnesium alloy furnaces and is employed in dry etching for semiconductor manufacturing. In the medical field, it is utilized in ophthalmology to reattach the retina by filling the eye post-vitrectomy, aiding the retina’s adherence to the eye wall.

Properties of Sulfur Hexafluoride

This colorless, odorless, nontoxic gas is chemically inert at room temperature. It has a melting point of -50.8°C and sublimates at -63.8°C. Water insoluble but slightly soluble in alcohol, inhaling sulfur hexafluoride can lower the pitch of one’s voice, due to its density compared to air.

Structure of Sulfur Hexafluoride

SF₆ consists of a sulfur atom surrounded by six fluorine atoms in an octahedral configuration, with a molecular weight of 146.06.

Other Information on Sulfur Hexafluoride

1. Synthesis of Sulfur Hexafluoride

It is synthesized by reacting elemental sulfur (S₈) with fluorine gas (F₂), yielding SF₆ along with byproducts like S₂F₁₀, which can be converted to other sulfur fluorides such as SF₅Cl.

2. Reaction of Sulfur Hexafluoride

Reactions of SF₆ are limited due to its non-polarity and stability. It can react with lithium to produce lithium fluoride and sulfide, a reaction utilized in torpedo propulsion due to the reduced volume of the reaction products.

3. Characteristics of Sulfur Fluoride

Among the six known sulfur fluorides, only disulfur decafluoride (S₂F₁₀) exists as a liquid at room temperature; the rest are gases. Sulfur tetrafluoride (SF₄) and other sulfur fluorides demonstrate the diverse chemistry of sulfur and fluorine.

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What Is Sodium Sulfite?

Sodium sulfite is an inorganic compound, represented by the formula Na₂SO₃. It forms as sodium sulfite heptahydrate when sodium hydroxide and sulfur dioxide react and cool, transitioning to anhydrous sodium sulfite upon heating. This compound can also be synthesized from sodium hydrogen sulfite and sodium carbonate, commonly produced industrially by sulfur dioxide recovery from heavy oil combustion flue gases.

Uses of Sodium Sulfite

As an antioxidant in wine and a preservative in cosmetics and hair color, sodium sulfite finds extensive use in cosmetics, foods, and pharmaceuticals. It prevents fading in dried fruits and acts as a bleaching agent in foods like kanpyo and cooked beans. In photography, it serves as a retaining agent to prevent developer oxidation and to remove the fixing solution from film.

Properties of Sodium Sulfite

With a pH of approximately 9, sodium sulfite solutions are slightly alkaline. Exposed to air, sodium sulfite solutions and heptahydrate crystals gradually oxidize to sulfate, with the anhydrous form being more air stable. It reacts with weak acids, releasing sulfur dioxide.

Structure of Sodium Sulfite

Sodium sulfite exists as a colorless monoclinic crystal in its heptahydrate form, with a density of 1.56 g/cm³, and as a hexagonal crystal in its anhydrous form, with a density of 2.63 g/cm³. X-ray crystallography reveals a pyramidal SO₃^2- ion structure.

Other Information on Sodium Sulfite

1. Hazards of Sodium Sulfite

Linked to various adverse reactions including respiratory issues in asthmatics, sodium sulfite’s inclusion in fresh foods is restricted by the FDA, with required labeling for concentrations above 10 ppm. It can also cause skin reactions in cosmetics and medications.

2. Related Compounds of Sodium Sulfite

Sodium hydrogen sulfite, formed from sulfur dioxide and sodium sulfite, shares properties and uses with sodium sulfite, including its gradual oxidation to sulfate in air. Sodium bisulfite, another related compound, is used interchangeably with sulfite in solutions.

What Is Sodium Nitrite?

Sodium nitrite, a colorless to pale yellow crystalline powder, is the sodium salt of nitrous acid with the chemical formula NaNO₂, molecular weight 69.01, and CAS No. 7632-00-0. It is recognized as a food additive under JIS standards for both industrial chemicals and reagents.

Structure of Sodium Nitrite

The molecule comprises a sodium cation (Na⁺) and a nitrite anion (NO₂^–), with a bent structure between the nitrogen and oxygen atoms.

Properties of Sodium Nitrite

1. Physical Properties

With a melting point of 270°C and a decomposition temperature of 320°C, sodium nitrite is deliquescent, highly water-soluble, and displays slight solubility in alcohol and ether. Its aqueous solutions are mildly alkaline.

2. Other Characteristics

Its interaction with meat amines can form nitrosamines, potential carcinogens, sparking health concerns related to cancer risk.

Uses of Sodium Nitrite

1. Food Additive

As a food additive, it is crucial for coloration and preservation in meats like ham, sausage, and bacon, enhancing flavor, reducing odors, and preventing botulinum bacteria growth.

2. Medical Supplies

Used as a disinfectant for medical tools and a vasodilator for cyanide poisoning treatment, sodium nitrite holds significant medical utility.

3. Industrial and Analytical Uses

Its application extends to rust prevention in concrete, synthesis of organic compounds, textile bleaching, metal surface treatment, and as an analytical reagent.

Other Information on Sodium Nitrite

1. Manufacturing Process

Produced by the reaction of sodium hydroxide with nitrogen oxides, sodium nitrite’s industrial synthesis involves specific chemical processes.

2. Regulatory Information

Regulated due to its toxic and oxidizing properties, sodium nitrite requires careful handling as per the Poisonous and Deleterious Substances Control Law and other regulations.

3. Handling and Storage Precautions

Storage and handling precautions include keeping it in a cool, dry place, using protective gear, and following safety measures to prevent accidents and health issues.

What Is Sodium Chlorite?

Sodium chlorite, with the formula NaClO₂, is the sodium salt of chlorous acid. Recognized by its CAS number 7758-19-2, it serves primarily as an oxidizing or bleaching agent, notable for its potent oxidizing power and distinctive pungent odor.

Uses of Sodium Chlorite

Its main applications include bleaching textiles like pulp, cotton, and hemp; decolorizing paper, fats, oils, and sucrose; surface treatment of printed circuit boards; denitration; and wastewater treatment. Sodium chlorite is a food additive, used as a bleaching agent and disinfectant, albeit with the condition of its removal before food consumption. It is also utilized in water treatment disinfection and as a cleaning agent for contact lenses.

Properties of Sodium Chlorite

Sodium chlorite appears as colorless, hygroscopic crystals at room temperature, with a molecular weight of 90.44 and decomposes between 180-200°C. It has a density of 2.5 g/mL and dissolves well in water (39 g/100 ml).

Types of Sodium Chlorite

Available as both a research reagent and an industrial chemical, sodium chlorite is marketed in various forms and concentrations.

1. Reagent Products for Research and Development

For laboratory use, it comes in quantities like 5g, 100g, 500g, 2kg, and 10kg, often with sodium carbonate as an impurity. Primarily used in synthetic organic chemistry as an oxidizing agent, these reagents are stored at room temperature.

2. Industrial Chemicals

Industrially, sodium chlorite is available both as a pure substance and in solution (e.g., 25% solution), predominantly used for its bleaching and oxidizing properties. Purchasers typically consult manufacturers for specific volumes.

Other Information on Sodium Chlorite

1. Synthesis of Sodium Chlorite

It is produced by reacting chlorine dioxide with sodium hydroxide and hydrogen peroxide.

2. Chemical Reaction of Sodium Chlorite

Sodium chlorite generates chlorine dioxide when treated with chlorine or sodium hypochlorite in aqueous solution, also producible by electro-oxidation or UV light exposure. It decomposes thermally into sodium chlorate and chloride, and is used in synthetic organic chemistry, particularly in oxidation reactions.

3. Hazardous Properties of Sodium Chlorite and Regulatory Information

As a strong oxidant, sodium chlorite poses risks of toxicity, skin and eye damage, organ harm (specifically to the spleen) upon prolonged exposure, and is highly toxic to aquatic life. It is regulated under multiple laws, classified as a hazardous substance, necessitating strict handling and labeling as per legal requirements.

What Is Phosphorous Acid?

Figure 1. Synthesis of Phosphorous Acid

Phosphorous acid is an inorganic phosphorus oxoacid, chemically represented by H₃PO₃. It belongs to the family of phosphorus oxoacids, including phosphoric acid and hypophosphorous acid. Phosphorous acid can be synthesized through the hydrolysis of acid anhydrides, typically by reacting phosphorus trichloride with water or steam. Notably, it has gained attention for its application in fertilizers. Pure phosphorous acid can be extracted from potassium phosphorous acid by treating it with hydrochloric acid, followed by concentration with alcohol or precipitation.

Uses of Phosphorous Acid

Phosphorous acid serves multiple roles, including as a catalyst and reducing agent in organic compound synthesis and as a stabilizer in vinyl chloride production. It is also a precursor for phosphite fertilizers. Despite phosphoric acid being a common component in phosphate fertilizers, phosphorous acid has emerged as an alternative due to its lower molecular weight, better solubility, and superior crop absorption and soil adsorption characteristics. This acid is found in both granular and liquid fertilizers, often combined with potassium, enhancing crop yield and quality when used correctly.

Properties of Phosphorous Acid

At room temperature and pressure, phosphorous acid appears as stable white crystals but is deliquescent. In aqueous solution, it primarily exists as HP(O)(OH)₂, demonstrating divalent acidity with a pH around 1. Its pK_a1 is 1.5 and pK_a2 is 6.79. Phosphorous acid is noted for its strong reducing properties, capable of liberating metals from solutions like silver nitrate, gold (III) chloride, and copper sulfate, with a standard redox potential of E° = -0.276 V in acidic solutions.

Structure of Phosphorous Acid

Phosphorous acid exhibits tautomerism, with hydrogen atoms shifting between phosphorus and oxygen. The predominant form is HP(O)(OH)₂, also known as phosphonic acid, over its trihydroxy counterpart, P(OH)₃. In solid form, phosphorous acid adopts a tetrahedral structure, with specific bond lengths for P-H, P-O, and P-O(H) bonds.

Other Information on Phosphorous Acid

1. Isomers of Phosphorous Acid

In solution, phosphorous acid exists in equilibrium with its tautomer, phosphonic acid, though phosphorous acid is the more prevalent form. In the realm of organic chemistry, phosphonic acids refer to compounds with the formula R-P(=O)(OH)₂, including substances like foscarnet, an antiviral drug. The diesters of P-alkylphosphonic acid are key substrates in the Horner-Wadsworth-Emmons reaction, pivotal for synthesizing alkenes.

2. Phosphorous Acid Related Compounds

Phosphorous acid is part of the broader phosphorus oxoacid family. Phosphorus oxoacids with an oxidation state of +5 include phosphoric acid, diphosphoric acid, triphosphoric acid, and meta-triphosphoric acid, among others. Phosphinic acid, with a phosphorus oxidation state of +1, is another related compound, expressed as H₃PO₂.