月: 2023年1月

What Is Butyric Acid?

Butyric acid, also known as orthobutyric acid, is a four-carbon aliphatic carboxylic acid. It is an oily, colorless liquid with an unpleasant odor reminiscent of rancid butter. Even in minimal quantities, mammals can detect its scent. It has a structural isomer known as isobutyric acid.

Butyric acid occurs naturally in animal milk fat as glycerides and in plant essential oils as esters. It is also produced through the fermentation of sugars and lactic acid and can be synthesized industrially by the oxidation of butyraldehyde and butanol.

Uses of Butyric Acid

Butyric acid serves various functions, including as a raw material for varnish production, organic synthesis (e.g., 4-heptanone), and emulsifiers. It’s a precursor for biofuel production and, when esterified, is used in synthetic fragrance manufacturing. Additionally, it finds applications in food processing, flavor enhancers, animal feed to boost nutrition and prevent diseases, and pharmaceuticals for treating cancer and irritable bowel syndrome.

Properties of Butyric Acid

With a density of 0.96 g/cm³ and a molecular weight of 88.11, butyric acid has a melting point of -7.9°C and a boiling point of 164°C. It is miscible with water, ethanol, and ether, and insoluble in brine, allowing for separation by salt addition. As a weak acid, its pKa is 4.82, making it slightly more acidic than acetic acid (pKa = 4.76).

Its chemical structure is CH₃(CH₂)₂COOH, and it is sometimes referred to as butanoic acid or n-butanoic acid.

Other Information on Butyric Acid

1. Butyric Acid in Nature

Derived from butter (Latin butyrum), butyric acid is biosynthesized during fatty acid breakdown and is widely present in nature. It contributes to the distinctive odors of body secretions, such as sebum and sweaty feet, and is found in cheese, butter, and certain plants like ginkgo biloba.

2. Butyric Acid as a Source of Energy

In herbivores, butyric acid is a vital energy source, produced by the anaerobic fermentation of cellulose and hemicellulose in the digestive system. It undergoes beta-oxidation to form acetyl-CoA, fueling the citric acid cycle. In the colon, it serves as a preferred energy source for colon cells and has anti-inflammatory properties, aiding intestinal repair.

3. Structural Isomers of Butyric Acid

Isobutyric acid, or 2-methylpropionic acid, is a structural isomer of butyric acid, with the formula (CH₃)₂CHCOOH. It occurs naturally, sometimes in esterified form in certain plants.

4. Related Compounds of Butyric Acid

Propionic acid (CH₃CH₂COOH) and pentanoic acid (CH₃(CH₂)₃COOH), also known as yoshinoic acid, are related saturated fatty acids, containing three and five carbon atoms, respectively.

What Is Sodium Acetate?

Sodium acetate is a compound formed from acetate and sodium ions.

It is produced by the neutralization reaction of acetic acid with sodium hydroxide. Known also by its chemical formula, CH₃COONa, sodium acetate has a molecular weight of 82.03. It exists in both anhydrous and trihydrate forms, both of which are white, crystalline substances at room temperature, and highly soluble in water.

Sodium acetate acts as a flame retardant and is considered a safe substance, commonly used as a food additive.

Uses of Sodium Acetate

Sodium acetate has various applications:

1. Reagent

As a reagent, sodium acetate is used to create buffer solutions that maintain a constant pH level, even when small amounts of acid or base are added. These buffer solutions are employed in HPLC (high-performance liquid chromatography) analyses.

2. Food Additive

As a food additive, sodium acetate helps extend the shelf life of food products by inhibiting the growth of microorganisms. It’s also used to adjust the acidity of sauces and mayonnaise.

3. Mordant

Sodium acetate enhances the adhesion of dyes to fabrics. For instance, adding sodium acetate to persimmon tannin dye improves its binding to linen.

Additionally, sodium acetate finds use in pharmaceuticals, photographic chemicals, plating agents, dehydrating agents, and as a catalyst in organic synthesis.

Properties of Sodium Acetate

Sodium acetate, a salt of acetic acid (a weak acid) and sodium hydroxide (a strong base), dissociates in water into acetate (CH₃COO^–) and sodium ions (Na⁺).

CH₃COONa → CH₃COO^– + Na⁺

In aqueous solutions, acetate ions often react with hydrogen ions to form acetic acid molecules, leading to a slightly basic solution (pH 7 to 9). Sodium acetate’s solubility in water at 20°C is 46.4 grams per 100 grams of water, indicating it should be stored in a dry environment to maintain its stability.

Types of Sodium Acetate

Sodium acetate is available in various grades for different applications, including pharmaceutical testing, food additives, reagent special grade, and industrial use, with quantities ranging from 25 grams to 20 kilograms. Solutions are also available in 100 and 500-milliliter volumes.

Other Information on Sodium Acetate

1. Synthesis of Sodium Acetate

Sodium acetate can be synthesized by several methods:

• Reacting acetic acid with sodium hydroxide: CH₃COOH + NaOH → CH₃COONa + H₂O
• Reacting acetic acid with sodium carbonate: CH₃COOH + Na₂CO₃ → CH₃COONa + NaHCO₃
• Reacting calcium acetate with sodium sulfate: Ca(CH₃COO)₂ + Na₂SO₄ → 2CH₃COONa + CaSO₄

2. Application to Heat Packs

Sodium acetate trihydrate is utilized in reusable heat packs. Sealed in a plastic bag and melted by heating above its melting point, it remains liquid even when cooled down. Physical stimulation triggers crystallization, releasing heat in the process. This feature makes it a convenient, reusable warming tool.

What Is Potassium Acetate?

Potassium acetate is a potassium salt of acetic acid.

Its molecular formula is CH₃COOK, and its molecular weight is 98.14. It is produced through the neutralization reaction of acetic acid with potassium hydroxide or potassium carbonate. At room temperature, it appears as a colorless or white crystalline powder.

Potassium acetate is deliquescent; thus, it requires careful storage. It may react violently with strong oxidizers or decompose upon contact with strong acids. However, potassium acetate is not regulated under the poisonous substances control or safety and fire laws.

Uses of Potassium Acetate

Potassium acetate serves various purposes in pharmaceuticals, as an anti-freeze, and as a research reagent.

1. Pharmaceuticals

Following diarrhea, vomiting, or surgery, the body may experience potassium deficiency. Potassium acetate is used in pharmaceuticals to replenish such deficiencies. It plays a role in regulating heart and muscle functions due to the potassium ions.

2. Anti-freeze Agent

As an anti-freeze agent, potassium acetate is advantageous because it is not corrosive to metals, unlike sodium chloride-based agents, and is biodegradable. It is thus considered an environmentally friendly solution for preventing ice formation on road surfaces.

3. Research Reagent

In molecular biology, a mixture of potassium acetate and acetic acid, pH-adjusted to around 5, is utilized for plasmid DNA extraction, facilitating the separation of desired plasmid DNA from other materials.

Besides, potassium acetate is employed in a wide array of applications including as an analytical reagent, dehydrating agent, fire extinguishing agent, and raw material for organic synthesis.

Properties of Potassium Acetate

Potassium acetate emits a slight acetic acid odor and has a specific gravity of 1.6 g/cm³. It melts at 292°C. Being a salt derived from a weak acid (acetic acid) and a strong base (potassium hydroxide), it ionizes in water to produce acetate ions and potassium ions.

CH₃COOK → CH₃COO^– + K⁺

In aqueous solutions, acetate ions react with hydrogen ions, leading to a slightly basic solution (pH 7.5 to 9.0). This is because acetate ions can combine with hydrogen ions from water ionization, forming acetic acid and shifting the solution to a more basic pH.

Potassium acetate dissolves well in water—256 grams per 100 grams of water at 20°C—and is also soluble in ethanol (C₂H₅OH).

Types of Potassium Acetate

Available in various grades, including reagent grade and grade 1, potassium acetate is sold in quantities of 25 g, 500 g, and 20 kg. Solutions for industrial use are available in 25 kg and 250 kg containers.

Other Information on Potassium Acetate

1. Synthesis of Potassium Acetate

Reaction of potassium acetate with potassium hydroxide

　　CH₃COOH + KOH → CH₃COOK + H₂O

Reaction of potassium acetate and potassium carbonate

　　2CH₃COOH + K₂CO₃ → 2CH₃COOK + CO₂ + H₂O

2. Reaction With Strong Oxidizers

Reaction of potassium acetate with potassium permanganate

　　14CH₃COOK + 16KMnO₄ → 16Mn + 15K₂CO₃ + 13CO₂ + 21H₂O

3. Reaction With Strong Acids

Reaction of potassium acetate with hydrogen chloride

　　CH₃COOK + HCl → KCl + CH₃COOH

Reaction of potassium acetate with hydrogen iodide

　　CH₃COOK + HI → KI + CH₃COOH

4. Decomposition Reaction

Formation of acetic acid

　　2CH₃COOK → 2KOH + CH₃COOH + 2C

What Is Isopropyl Acetate?

Isopropyl acetate, a versatile organic compound known by names such as 1-methylethyl acetate and 2-acetoxypropane, serves a broad range of applications, from solvent use to flavorings, due to its clear colorless appearance and characteristic fruity aroma.

Uses of Isopropyl Acetate

Employed widely as a solvent in the adhesive, paint, and printing ink industries, and as a flavor and fragrance ingredient, isopropyl acetate showcases its utility in both industrial processes and consumer products.

Properties of Isopropyl Acetate

With a molecular formula of C₅H₁₀O₂, it exhibits low boiling and melting points, high solubility in organic solvents, and a notable fruity scent, alongside significant flammability and reactivity considerations.

Other Information on Isopropyl Acetate

1. Production Process of Isopropyl Acetate

The synthesis of isopropyl acetate involves condensation reactions facilitated by catalysts, highlighting its manufacturing from isopropanol or propylene and acetic acid.

2. Regulatory Information

Governed by various safety regulations due to its flammability and potential health hazards, isopropyl acetate demands careful handling and adherence to legal standards in its use and storage.

3. Precautions for Handling and Storage

Emphasizing the need for preventive measures against its flammable nature and the risks posed by inhalation, detailed precautions outline the importance of safety in its handling and storage, including measures in case of fire or exposure.

What Is Ammonium Acetate?

Ammonium acetate, also known as ammonium ethanoate, is an organic ammonium salt with the formula CH₃COONH₄. With a molecular weight of 77.08 and a melting point of 112°C, it forms white or colorless crystals that are highly soluble in water and ethanol.

Recognized for its weak odor reminiscent of ammonia and acetic acid, it exhibits deliquescent properties. Its significant solubility in water and non-hazardous classification under various safety laws make it a versatile compound in numerous applications.

Uses of Ammonium Acetate

Ammonium acetate finds utility in reagent and buffer preparations, yeast culture mediums, desulfurization catalysts, and food preservation, showcasing its broad applicability in analytical chemistry, pharmaceuticals, and industrial processes.

Properties of Ammonium Acetate

As a salt of a weak acid and a weak base, it demonstrates strong buffering capabilities and is used in making buffer solutions. Its hygroscopic nature and stability under normal conditions are noted, with precautions advised against moisture, heat, and oxidizing agents.

Types of Ammonium Acetate

Available mainly for R&D and industrial applications, ammonium acetate is sold in various quantities, from small laboratory sizes to large industrial volumes, catering to a wide range of uses from analytical buffers to biodegradable de-icing agents.

Other Information on Ammonium Acetate

1. Synthesis of Ammonium Acetate

Produced through the neutralization of glacial acetic acid with ammonia or ammonium carbonate, its synthesis highlights its chemical flexibility.

2. Chemical Reaction of Ammonium Acetate

Facilitates Knoevenagel condensation as a catalyst, demonstrating its role in organic synthesis. Its decomposition into acetamide, and subsequent conversion processes, underscore its chemical reactivity and potential for further transformations.

What Is Calcium Peroxide?

Calcium peroxide, a calcium peroxide compound with the formula CaO₂, is recognized for its use across various fields. Despite being nonflammable, it poses explosive risks when in contact with organic matter.

Its diverse applications range from agriculture to dentistry, highlighting its role in environmental purification and as a bleaching agent.

Uses of Calcium Peroxide

From serving as a soil conditioner and fungicide to aiding in water purification and food processing, calcium peroxide’s versatility is evident.

1. Agricultural Applications

Revitalizes nutrient-depleted soils and oxygen-starved water bodies, paralleling the effects of magnesium peroxide in enhancing environmental quality.

2. Other Fields

Beyond agriculture, it finds utility in paper bleaching, dental treatments, and as a food additive, among other applications.

Properties of Calcium Peroxide

This white or yellowish powder is characterized by its oxidizing nature, insolubility in water, and reaction with acids to produce hydrogen peroxide. Caution is warranted due to its explosive decomposition potential at elevated temperatures.

Types of Calcium Peroxide

Available primarily for R&D purposes, calcium peroxide is sold in various quantities and purities, typically containing calcium hydroxide as an impurity.

Other Information on Calcium Peroxide

1. Synthesis of Calcium Peroxide

Produced by reacting calcium hydroxide with hydrogen peroxide, its synthesis underscores its chemical versatility.

2. Hazards of Calcium Peroxide

Its classification under the GHS highlights the importance of proper handling and storage to mitigate physicochemical and health hazards.

3. Regulatory Information on Calcium Peroxide

Subject to various regulations due to its hazardous nature, compliance with safety laws is imperative for its management and application.

What Is Sodium Percarbonate?

Sodium percarbonate or sodium peroxocarbonate, is a compound of sodium carbonate and hydrogen peroxide. This white crystalline powder dissolves in water and is a powerful oxidizing agent. Sodium percarbonate poses a risk of fire or explosion upon contact with water, especially above 50°C.

Its efficacy as a non-chlorine bleach has made it a preferred choice in various cleaning applications, offering an environmentally friendly alternative to traditional chlorine-based products.

Uses of Sodium Percarbonate

Utilized for its bleaching, disinfecting, and deodorizing properties, sodium percarbonate is employed in both household and industrial settings.

1. Bleaching Agent

Effectively bleaches fabrics and garments without damaging fibers or producing harsh odors, unlike chlorine bleach.

2. Cleaning Agent

Cleans residential surfaces, piping, and medical equipment, offering a versatile cleaning solution.

3. Disinfectant Bleach Cleaning Agent

Used for sanitizing diapers and dentures, ensuring hygiene in sensitive applications.

4. Industrial Treatment Agents

Acts as a textile bleacher, pollution control agent, and semiconductor manufacturing cleaner. Additionally, it serves as an emergency oxygen gas generator and hair dye oxidizing agent.

Properties of Sodium Percarbonate

Stable at room temperature, this odorless powder forms an alkaline solution upon dissolution, showcasing strong oxidizing capabilities.

Reacts with various materials, necessitating careful handling and storage away from flammable and reducing substances, and certain metals.

Structure of Sodium Percarbonate

The compound features two sodium ions linked to a carbonate and hydrogen peroxide, highlighting its ionic and oxidizing nature.

Other Information on Sodium Percarbonate

1. Production Methods

Produced via wet or dry processes, with stabilization often achieved by salts to remove impurities or as chelating agents.

2. Common Uses

Marketed as a superior cleaning agent, effective against stubborn stains and discolorations, compared favorably to other household cleaners for its higher pH and efficacy.

3. Comparison with Sodium Peroxide

Distinguished from sodium peroxide by its safety profile and application, sodium percarbonate offers a less reactive, more user-friendly option for cleaning and bleaching.

What Is Lithium Perchlorate?

Lithium perchlorate, with the formula LiClO₄, is the lithium salt of perchloric acid, known for its excellent solubility in both water and organic solvents. It’s produced by reacting lithium chloride with sodium perchlorate.

As a common trait among perchlorates, it acts as an oxidizing agent and displays chaotropic behavior, disrupting water molecule networks due to its large ionic radius in solution.

Uses of Lithium Perchlorate

Its versatility is highlighted in applications ranging from electrolytes in lithium-ion batteries to catalysts in organic reactions, thanks to its high solubility and strong acid-base composition.

1. Lithium-Ion Batteries

As a vital electrolyte component, it enhances lithium-ion batteries and lithium-sulfur batteries’ performance.

2. Conductivity Enhancer

Improves conductivity in polymers, acting as a conductive additive.

3. Catalyst

Facilitates various organic chemical reactions as a Lewis acid due to its solubility in organic solvents.

4. Oxygen Source

Serves as an efficient oxygen source in chemical oxygen generators, due to its high oxygen content.

5. Chaotropic Agent

Used to denature proteins in highly concentrated solutions.

Properties of Lithium Perchlorate

It is offered in anhydrous and trihydrate forms, both exhibiting high solubility in water and organic solvents, alongside notable oxidizing properties.

1. Appearance, Solubility, Crystals

Characterized by its white color, odorlessness, and deliquescent nature (trihydrate form), lithium perchlorate’s solubility makes it invaluable across various applications.

2. Oxidizing Power

Its strong oxidizing ability stems from the chlorine in its highest oxidation state, capable of oxidizing adjacent substances.

Other Information on Lithium Perchlorate

1. Properties When Heated

Decomposes into lithium chloride and oxygen around 400℃, necessitating careful storage away from organic matter and reducing agents to prevent fires.

2. Hazards and Toxicity

GHS classified as an oxidizing solid with potential for serious eye damage and skin irritation, also noted for reproductive toxicity.

3. Related Laws and Regulations

Regulated under various safety and transport laws due to its oxidizing properties and potential contribution to combustion and explosion risks.

What Is Ammonium Perchlorate?

Ammonium perchlorate, an inorganic compound with the formula NH₄ClO₄, is produced by reacting perchloric acid and ammonia or adding ammonium chloride to a sodium perchlorate solution. As a potent oxidizing agent containing nitrogen and hydrogen, it is an efficient propellant in explosives and rockets, minimizing waste.

Uses of Ammonium Perchlorate

Its primary use is as an oxidizer in explosives, fireworks, and rocket propellants.

1. Explosives

Used as an oxidizer in Carlit, an industrial explosive, combined with silicon iron and wood powder for combustion.

2. Fireworks

It produces a bright white light when mixed with aluminum and magnesium powders, making it ideal for fireworks, distress signals, and flares.

3. Rocket Propellant

Ammonium perchlorate is a preferred oxidizer in solid-fuel rockets, offering high efficiency but producing toxic gases such as hydrogen chloride upon combustion.

Properties of Ammonium Perchlorate

1. Appearance and Solubility

This colorless or white crystalline solid is odorless, water-soluble, partially soluble in acetone, and insoluble in ether. Its stability in neutral solutions poses environmental risks.

2. Oxidizing Power

The high oxidation state of chlorine in perchlorates provides significant oxidizing power, with ammonium perchlorate being particularly reactive due to its ammonia content.

3. Explosion Hazard

Dry ammonium perchlorate is highly explosive and can be less so when stabilized with water. It remains explosive with organic materials and combustible metals.

4. Heating and Fire Hazard

Begins decomposing around 150°C, with thermal decomposition risking explosion. Organic materials, reducing agents, and physical shocks increase fire risks, producing toxic gases.

Other Information on Ammonium Perchlorate

1. Hazards and Toxicity

Classified by GHS as an explosive, oxidizing solid, with skin, eye, and respiratory irritants.

2. Related Laws and Regulations

Regulated under various laws for its hazardous and oxidizing properties, but not classified as a poisonous and deleterious substance.

What Is Sodium Permanganate?

Sodium permanganate, with the chemical formula NaMnO₄, is a potent oxidizer, sharing basic chemical properties with potassium permanganate, including strong oxidizing power. It is notably more soluble in water than potassium permanganate.

Produced from manganese oxide and sodium hypochlorite, it decomposes, releasing oxygen when heated.

Uses of Sodium Permanganate

As a strong oxidizer, sodium permanganate is commonly available as a 40% aqueous solution. Its applications range from analytical reagents, removing manganese and iron, eliminating odor and organic matter, sewage and industrial effluent treatment, textile bleaching, inorganic and organic acid purification, and pharmaceutical production, to tanker cleaning. It also serves as an etching agent in electronics and a fixing agent in electron microscopy.

Properties of Sodium Permanganate

This dark reddish-purple liquid has a molecular weight of 141.93 g/mol and a boiling point of 100°C, with a density of 1.391 Pcm³. It is chemically stable under normal conditions but should be kept away from incompatible materials such as metal powders and strong acids.

Other Information on Sodium Permanganate

1. Safety

Classified under GHS for various hazards, sodium permanganate can cause serious health risks including skin burns, eye damage, and potential chronic manganese poisoning affecting the nervous system. It also poses environmental risks.

2. First Aid Measures

Includes immediate rinsing for ingestion or skin contact, careful eye washing, and precautionary measures for first aid personnel, including protective equipment.

3. Handling Instructions

Recommendations for safe handling include avoiding heat and ignition sources, using personal protective equipment, and thoroughly washing after handling.

4. In the Case of Fire

Advises against using sodium permanganate as a fire extinguishing agent, highlights potential fire-aggravating effects due to oxygen release, and suggests protective measures for firefighters.

5. Applicable Laws and Regulations

Sodium permanganate is not classified as a hazardous material or a poisonous and deleterious substance.