月: 2023年1月

What Is Amyl Nitrite?

Amyl nitrite is an organic compound, an ester of nitrite, with the molecular formula C₅H₁₁NO₂. While amyl nitrite typically refers to a group of isomeric nitrite esters, this section focuses on both n-amyl nitrite and isoamyl nitrite, each having a molecular weight of 117.15.

1. N-Amyl Nitrite (N-Pentyl Nitrite)

n-Amyl nitrite, or Pentyl Nitrite, is a clear yellowish liquid at room temperature, with a boiling point of 104-105 °C. It has a sweet smell and a density of 0.836 g/mL. This compound decomposes upon contact with water, is practically insoluble (solubility 3.97 g/L), but is miscible with organic solvents like ethanol, ether, and chloroform. Its CAS registration number is 463-04-7.

2. Isoamyl Nitrite (Isopentyl Nitrite)

Isoamyl nitrite, also known as Isopentyl nitrite, is a clear yellowish liquid with a fruity odor and a density of 0.875 g/mL. It boils at 99 °C and is practically insoluble in water, but miscible with chloroform, ethanol, and ether. The flash point of isoamyl nitrite is 3 °C.

Uses of Amyl Nitrite

Isoamyl nitrite is used in cardiac medications for conditions like angina pectoris and as an antidote for cyanide poisoning. It is also used as an inhalant due to its vaporizing tendency and sometimes as an antidote for hydrogen sulfide poisoning. A small amount can be absorbed onto a piece of cloth and inhaled to alleviate seizures immediately.

Principle of Amyl Nitrite

The principles of amyl nitrite are rooted in its chemical properties. Amyl nitrite is synthesized through the esterification of amyl alcohol with nitric acid. It’s used in organic chemistry for diazotization of primary amines and N-nitrosation of secondary amines. A typical application is in the Sandmeyer reaction, involving halogen substitution in aromatic rings.

2. Principle of Cyanide Detoxification by Isoamyl Nitrite

Isoamyl nitrite works in cyanide detoxification by oxidizing the Fe²⁺ in hemoglobin to Fe³⁺ methemoglobin. This inhibits the binding of cyanide to cytochrome oxidase. Additionally, when administered with sodium thiosulfate, it helps convert cyanogen to thiocyanate, aiding detoxification.

Types of Amyl Nitrite

Both n-amyl nitrite and isoamyl nitrite are sold under the name amyl nitrite. However, they can be distinguished in chemical reagents by their aliases or CAS registry numbers. Drugs labeled as amyl nitrite predominantly contain isoamyl nitrite.

What Is Nitrogen Dioxide?

Nitrogen dioxide, a reddish-brown gas with a pungent odor, is a significant air pollutant produced primarily from combustion processes, notably in automobile engines. It’s involved in the formation of acid rain and ozone, posing health risks, especially to the respiratory tract.

Uses of Nitrogen Dioxide

It finds applications in analytical chemistry, manufacturing of nitrogen compounds, as a bleaching and nitrosating agent, and as an oxidizer in rocket fuels, notably used in historic space missions.

Properties of Nitrogen Dioxide

Nitrogen dioxide transitions from a reddish-brown gas to a yellow liquid and then to colorless dinitrogen tetroxide under varying temperatures, demonstrating its ability to absorb blue light and participate in photolysis. It is paramagnetic due to an unpaired electron.

Structure of Nitrogen Dioxide

With the chemical formula NO₂, it exhibits C_2v symmetry, showcasing bond lengths and angles intermediate between its cationic and anionic forms.

Other Information on Nitrogen Dioxide

1. Synthesis of Nitrogen Dioxide

Produced industrially by oxidizing ammonia or through the reaction of concentrated nitric acid with metals, nitrogen dioxide is also a byproduct of combustion and natural biological activity, contributing to urban air pollution.

2. Reactions of Nitrogen Dioxide

It’s involved in equilibrium with dinitrogen tetroxide, contributes to acid rain through its reaction with water, and reacts with sulfur dioxide to produce nitric oxide and sulfur trioxide.

3. Environmental Pollution Caused by Nitrogen Dioxide

Regulated under air pollution control laws, nitrogen dioxide levels have stabilized due to emission controls, yet concentrations near major roads frequently exceed environmental standards, highlighting ongoing challenges in air quality management.

What Is Carbon Dioxide Gas?

Carbon dioxide gas (CO₂) is a colorless, odorless gas vital to the Earth’s natural carbon cycle, produced by organisms and consumed by plants. It’s emitted from combustion and industrial processes, with its solid form known as dry ice and its aqueous solution as carbonated water.

Uses of Carbon Dioxide Gas

CO₂ is used in various industries, including the chemical industry, food preservation, beverage carbonation, fire extinguishing, and as a raw material for industrial products. It’s also involved in urethane foam production but is recognized as a contributor to global warming, highlighting the importance of emission reduction.

Properties of Carbon Dioxide Gas

Present in trace amounts in the air, CO₂ is soluble in water, forming slightly acidic carbonated water. It sublimates directly from solid to gas and is used as a fire-extinguishing agent due to its nonflammability and density. Caution is advised due to its toxic properties.

Other Information on Carbon Dioxide Gas

1. How Carbon Dioxide Gas Is Produced

Industrially produced from fermentation gas, natural gas, and byproduct gases, it’s purified through various methods to produce liquefied CO₂ and dry ice, used in different applications.

2. Greenhouse Effect of Carbon Dioxide Gas

As a greenhouse gas, CO₂ contributes to global warming with its absorption of infrared rays. Efforts to reduce emissions include anthropogenic reduction, afforestation, and the development of carbon dioxide gas capture and storage (CCS) technology.

3. Efforts to Capture and Separate Carbon Dioxide Gas

To combat global warming, technologies such as direct air capture (DAC), chemical and physical adsorption, membrane separation, and utilization of CO₂ as a raw material are being developed and commercialized, with significant international involvement.

What Is Thiourea Dioxide?

Thiourea dioxide, an organosulfur compound known as formamidine sulfinic acid, is a flammable substance that ignites upon contact with moisture. It serves as a powerful reducing agent across various industries including leather processing, paper, photography, textile processing, and more, due to its thermal stability and excellent reducing properties.

Uses of Thiourea Dioxide

It is instrumental in bleaching and decolorizing textiles, paper recycling, and leather processing, among other uses. Thiourea dioxide also plays a role in organic synthesis, pharmaceutical manufacturing, and precious metals recovery.

Properties of Thiourea Dioxide

This compound appears as a white or pale yellow powder with a molecular weight of 108.12 and decomposes at 144°C without melting. It’s slightly soluble in water but mostly insoluble in ethanol, acetone, ether, and benzene.

Types of Thiourea Dioxide

Available in various capacities for both research and industrial applications, thiourea dioxide comes in sizes ranging from laboratory-friendly quantities to large industrial packages.

Other Information on Thiourea Dioxide

1. Synthesis of Thiourea Dioxide

Typically produced through the oxidation of thiourea with hydrogen peroxide.

2. Toxicity of Thiourea Dioxide

It poses several health hazards, including the risk of fire, toxicity if ingested or inhaled, irritation to skin and eyes, and potential damage to internal organs with prolonged exposure.

3. Regulatory Information and Precautions for Handling Thiourea Dioxide

Given its flammability and health risks, thiourea dioxide must be handled with care, employing proper ventilation and protective gear to mitigate exposure.

What Is Carbon Disulfide?

Carbon disulfide, a volatile liquid with the chemical formula CS₂, is used extensively as a solvent and raw material in organic synthesis. Found in trace amounts in coal and crude oil, it is notable for its use in the production of cellophane, and rayon, and as a vulcanization accelerator for rubber.

Uses of Carbon Disulfide

Its utility spans from being a solvent for phosphorus, sulfur, and selenium, to being used in the purification of single-walled carbon nanotubes, and as an insecticide. It’s also significant in the dissolution of organic compounds for NMR measurements.

Properties of Carbon Disulfide

With a melting point of -112.1°C and a boiling point of 46°C, carbon disulfide is known for its high volatility and flammability. It has a distinctive ethereal aroma in its pure form but generally possesses a foul odor due to impurities.

Other Information on Carbon Disulfide

1. Production Process of Carbon Disulfide

Produced industrially by heating charcoal with sulfur vapor, or by reacting natural gas with sulfur vapor in the presence of a catalyst.

2. Reaction of Carbon Disulfide

It undergoes combustion to form sulfur dioxide and carbon dioxide and reacts with chlorine to give carbon tetrachloride. It also forms complexes with primary and secondary amines and alkoxides.

3. Regulatory Information

Regulated under various laws for its evaluation, manufacture, and impact on health and the environment, carbon disulfide is treated with strict handling and storage guidelines to mitigate risks.

4. Handling and Storage Precautions

• Store in a sealed, cool, dark place away from ignition sources.
• Use with appropriate protective gear and in well-ventilated areas.
• Avoid contact with strong oxidizers and ensure thorough cleaning after handling.

What Is Ethylene Dichloride?

Ethylene dichloride, known as dichloromethane or methylene chloride, is an organic compound formed through the radical reaction of methane or methyl chloride with chlorine. It’s the most stable methane chloride but susceptible to decomposition by light and oxygen over time, requiring careful storage.

Uses of Ethylene Dichloride

Valued for its flame-retardant properties and ability to dissolve numerous organic compounds, ethylene dichloride is utilized in various chemical reactions, metalworking industry as a cleaning agent, and in the production of polylactic acid and polyester polyol.

Properties of Ethylene Dichloride

This colorless liquid is known for its sweet aroma, high solubility in organic compounds, and immiscibility with water. With a melting point of -96.7°C and a boiling point of 40°C, it serves as an important solvent in organic chemistry.

Other Information on Ethylene Dichloride

1. Synthesis of Ethylene Dichloride

Produced industrially through the radical reaction of methane or chloromethane with chlorine, ethylene dichloride is one of several chlorinated methane derivatives obtained, necessitating purification by distillation.

2. Purification of Ethylene Dichloride

For use as a solvent, dehydration with molecular sieves or calcium hydride is recommended, avoiding sodium due to explosion risks.

3. Hazards of Ethylene Dichloride

Exposure can cause eye and skin irritation, anesthetic effects, central nervous system suppression, and liver dysfunction, with long-term exposure linked to bile duct cancer.

4. Restrictions on the Use of Ethylene Dichloride

Subject to reporting under safety laws, efforts are underway to limit its use in favor of environmentally friendly alternatives, with recycling and reuse practices being implemented.

What Is Sodium Lactate?

Sodium lactate, the sodium salt of lactic acid, is an odorless or slightly odorous compound that plays a critical role as a natural moisturizing factor in skin care. It’s known for its moisturizing effect, and pH buffering capacity, and is widely used in cosmetics, food additives, and pharmaceuticals. Produced by neutralizing lactic acid from sources like corn starch or sugar radish, sodium lactate is a testament to the versatility of lactic acid derivatives.

Uses of Sodium Lactate

Its application spans cosmetics, for its moisturizing and mild exfoliating effects; the food industry, as acidifiers, pH adjusters, seasonings, and preservatives; and pharmaceuticals, in parenteral and topical preparations, and infusions.

Properties of Sodium Lactate

Sodium lactate balances the properties of organic acid and hydroxyl group, rendering it nearly neutral and safe for the human body regarding pH. It exhibits neither strong acidity nor alkalinity.

Structure of Sodium Lactate

As the sodium salt of lactic acid, sodium lactate showcases the characteristics of hydroxy acids with its -COOH and -OH groups. It’s a key component in the synthesis of polymers like polylactic acid, highlighting its potential in biodegradable plastic production.

Other Information on Sodium Lactate

PH Buffer Solution Containing Sodium Lactate

Integral to quality control in food and cosmetics, sodium lactate serves as a pH buffer, maintaining stability against pH fluctuations. When combined with lactic acid, it forms a lactate buffer, part of a family of buffers including acetate, phosphate, and citrate, ensuring mild acidity and minimal impact on taste.

What Is Lactic Acid?

Lactic acid, a hydroxy acid with both carboxyl and hydroxy groups, is a colorless to pale yellow viscous liquid known as 2-hydroxypropanoic acid. It serves as a raw material for biodegradable plastics like polylactic acid and polyester polyol and finds uses in pharmaceuticals, the food industry as an acidifier, cosmetics, agrochemicals, dyeing, and leather processing.

Uses of Lactic Acid

Employed in producing methanol, and ammonia, and as a reducing agent, lactic acid also reacts with transition metals under catalyzed conditions to form important compounds like nickel carbonyl and cobalt carbonyl, used in synthetic organic chemistry.

Properties of Lactic Acid

Lactic acid is odorless, acidic, and has a molecular weight of 90.08. It is soluble in water, alcohol, and ether, and is the end product of the glycolytic metabolic pathway, found in animal tissues, and fermented milk products, and does not directly cause muscle pain post-exercise as previously believed.

Types of Lactic Acid

Due to its chiral carbon atom, lactic acid exists as L-lactic acid, D-lactic acid, and DL-lactic acid, each with distinct melting points and properties. L-lactic acid is the most abundant in nature.

Other Information on Lactic Acid

1. Production Methods of Lactic Acid

Lactic acid is produced either by fermentation using lactic acid bacteria or by chemical synthesis. The fermentation method involves malt juice and lactic acid bacteria, while the synthetic method uses acetaldehyde and cyanide for synthesis.

2. About Lactic Acid Bacteria

Lactic acid bacteria, used in the production of yogurt, and cheese, and during wine and sake brewing processes, produce lactic acid from carbohydrates. Malolactic fermentation enhances acidity and flavor in red wine, while in sake brewing, lactic acid helps prevent bacterial growth and adds subtle flavors and aromas.

What Is Chromium Oxide?

Chromium oxide is an inorganic compound with the chemical formula CrO3, also known as chromium(VI) oxide.

It is a dark red to orange-brown solid with a molecular weight of 99.99. It is obtained by reacting sodium chromate or sodium dichromate with sulfuric acid.

Millions of kilograms are produced industrially each year by this process. Chromium(VI) oxide is highly toxic, corrosive, and carcinogenic, and chromium, a constituent atom of chromium(IV) oxide, is hexavalent chromium, a substance known to cause environmental damage.

Uses of Chromium Oxide

Chromium oxide is mainly used as industrial raw material for chrome plating.

It is often used to react with cadmium, zinc, and other metals to form corrosion-resistant protective coatings of chromium.
Chromium oxide is also characterized by its transmission wavelength range in the infrared region and is used as an optical material in absorption coatings and electrochromic applications.

It is known that optical properties (refractive index and transmittance) are strongly affected by substrate temperature.
However, the film quality of chromium oxide is tough and is also used to provide corrosion resistance, anti-oxidation, abrasion resistance, and adhesion.

What Is Carbon Monoxide Gas?

Carbon monoxide gas, a carbon oxide variant, is colorless, odorless, flammable, and produced from the incomplete combustion of carbon or carbon compounds in low-oxygen conditions or from reducing carbon dioxide with coke at high temperatures. It’s available commercially in cylinders and prevalent in industrial air, and automobile exhaust, and is a primary cause of carbon monoxide poisoning. Due to its hazards, it is strictly regulated under various safety and health laws.

Uses of Carbon Monoxide Gas

As a versatile reducing agent in metallurgy and a component of gaseous fuel, carbon monoxide gas is essential in producing methanol, and ammonia, and serves as a catalyst precursor in synthetic organic chemistry, exemplified by its role in forming nickel carbonyl and cobalt carbonyl for the Reppe and oxo reactions.

Properties of Carbon Monoxide Gas

With a molecular formula of CO and a weight of 28.01, carbon monoxide gas features extremely low flash, melting, and boiling points, with an ignition point of 605-609°C. It forms metallic carbonyls, burns with a blue flame to become CO₂, and is dangerously toxic and explosive in air mixtures.

Other Information on Carbon Monoxide Gas

1. How Carbon Monoxide Gas Is Produced

Laboratory production involves dehydrating a mixture of sulfuric acid and formic acid. Industrially, it’s generated by high-temperature reactions of carbon with water vapor or hydrocarbon gas, with subsequent processing to purify and separate carbon monoxide and hydrogen gases.

2. Carbon Monoxide Gas Poisoning

Characterized by symptoms mimicking the common cold, carbon monoxide poisoning occurs from binding to hemoglobin, disrupting oxygen transport. Awareness and countermeasures like gas alarms are critical for safety in potential exposure areas.