கொஞ்சம் கெமிஸ்ட்ரி ! - EP.019

 

1. Steel

   • Composition: Iron and carbon (plus other elements like manganese, chromium, nickel)

   • Uses: Construction, automotive parts, machinery, tools

2. Stainless Steel

   • Composition: Iron, chromium (typically 10.5% or more), nickel, and other elements

   • Uses: Kitchenware, medical instruments, industrial equipment, architecture

3. Cast Iron

   • Composition: Iron and carbon (typically 2-4%), silicon

   • Uses: Cookware, pipes, automotive engine blocks, machinery

4. Brass

   • Composition: Copper and zinc

   • Uses: Musical instruments, decorative items, plumbing fixtures, electrical connectors

5. Bronze

   • Composition: Copper and tin (plus other elements like aluminum, silicon)

   • Uses: Bearings, bushings, coins, sculptures, electrical connectors

6. Aluminum Alloys

   • Composition: Aluminum and other elements like copper, magnesium, silicon, zinc

   • Uses: Aerospace, automotive parts, packaging, construction, consumer electronics

7. Titanium Alloys

   • Composition: Titanium and other elements like aluminum, vanadium

   • Uses: Aerospace, medical implants, marine equipment, sports equipment

8. Nickel Alloys

   • Composition: Nickel and other elements like chromium, iron, molybdenum

   • Uses: Turbine blades, gas turbines, chemical processing equipment, marine applications

9. Magnesium Alloys

   • Composition: Magnesium and other elements like aluminum, zinc, manganese

   • Uses: Aerospace, automotive parts, electronic devices, portable tools

10. Cobalt Alloys

    • Composition: Cobalt and other elements like chromium, molybdenum, tungsten

    • Uses: Medical implants, cutting tools, jet engines, gas turbines

11. Pewter

    • Composition: Tin, copper, antimony, bismuth (sometimes lead)

    • Uses: Tableware, decorative items, souvenirs, collectibles

12. Monel

    • Composition: Nickel and copper (plus iron, manganese)

    • Uses: Marine engineering, chemical processing, musical instruments, valves

13. Inconel

    • Composition: Nickel, chromium, iron (plus other elements like molybdenum, niobium)

    • Uses: Jet engines, gas turbines, chemical processing, high-temperature applications

14. Hastelloy

    • Composition: Nickel, molybdenum, chromium (plus other elements like tungsten, iron)

    • Uses: Chemical processing, aerospace, pollution control, marine applications

15. Duralumin

    • Composition: Aluminum, copper, manganese, magnesium

    • Uses: Aircraft structures, automotive parts, machinery

These alloys are carefully engineered to provide specific properties that meet the demands of various applications, ranging from everyday items to advanced industrial and aerospace components.

16. Titanium Alloys (e.g., Ti-6Al-4V)

    • Composition: Titanium, aluminum, vanadium

    • Uses: Aerospace components, medical implants, marine equipment

17. Silicon Bronze

    • Composition: Copper, silicon

    • Uses: Marine hardware, electrical connectors, screws and nuts

18. Nickel Silver (German Silver)

    • Composition: Copper, nickel, zinc

    • Uses: Musical instruments, cutlery, decorative items

19. Aluminum Bronze

    • Composition: Copper, aluminum

    • Uses: Marine hardware, bearings, bushings, gears

20. Babbitt Metal

    • Composition: Tin, lead, copper, antimony

    • Uses: Bearings, engine components, machinery

21. Gunmetal

    • Composition: Copper, tin, zinc

    • Uses: Bearings, bushings, gears, statues, cannons

22. Invar

    • Composition: Iron, nickel

    • Uses: Precision instruments, clocks, measuring devices

23. Manganese Bronze

    • Composition: Copper, zinc, manganese, iron, lead

    • Uses: Marine hardware, propellers, industrial gears

24. Sterling Silver

    • Composition: Silver, copper

    • Uses: Jewelry, tableware, coins

25. White Gold

    • Composition: Gold, nickel, palladium

    • Uses: Jewelry, dental alloys

26. Type Metal

    • Composition: Lead, antimony, tin

    • Uses: Printing type, linotype machines

27. Cupronickel

    • Composition: Copper, nickel

    • Uses: Marine hardware, coins, condenser tubes

28. Constantan

    • Composition: Copper, nickel

    • Uses: Thermocouples, resistors, strain gauges

29. Nichrome

    • Composition: Nickel, chromium

    • Uses: Heating elements, resistance wire, toasters

30. Soft Solder

    • Composition: Tin, lead (lead-free alternatives: tin, silver, copper)

    • Electronics, plumbing, metalwork

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.018

Here are the common types of plastic used in packaging:

1. Polyethylene Terephthalate (PET or PETE)

   • Properties: Lightweight, strong, transparent

   • Uses: Beverage bottles, food jars, microwaveable food trays

2. High-Density Polyethylene (HDPE)

   • Properties: Strong, resistant to moisture and chemicals

   • Uses: Milk cartons, detergent bottles, cereal box liners

3. Polyvinyl Chloride (PVC)

   • Properties: Hard, rigid, resistant to chemicals and weathering

   • Uses: Blister packaging, cling wraps, food foils

4. Low-Density Polyethylene (LDPE)

   • Properties: Flexible, transparent, resistant to oils and acids

   • Uses: Plastic bags, stretch film, squeezy condiment bottles

5. Polypropylene (PP)

   • Properties: High melting point, chemical resistance, low moisture transmission

   • Uses: Medicine bottles, yogurt containers, take-out food containers

6. Polystyrene (PS)

   • Properties: Lightweight, rigid, insulating

   • Uses: Disposable cutlery, foam cups, food containers

7. Polycarbonate (PC)

   • Properties: Strong, transparent, impact-resistant

   • Uses: Reusable water bottles, food storage containers, eyewear lenses

8. Polyethylene (PE)

   • Properties: Versatile, durable, resistant to chemicals

   • Uses: Grocery bags, shrink wrap, bottle caps

9. Polyamide (Nylon)

   • Properties: Strong, flexible, resistant to abrasion

   • Uses: Vacuum packaging, meat and cheese packaging

10. Ethylene Vinyl Alcohol (EVOH)

    • Properties: Excellent barrier to gases and odors

    • Uses: Food packaging, especially for perishable items

11. Polyethylene Naphthalate (PEN)

    • Properties: High strength, excellent barrier properties

    • Uses: Beverage bottles, food containers

12. Polylactic Acid (PLA)

    • Properties: Biodegradable, compostable

    • Uses: Food packaging, disposable cutlery, compostable bags

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.017

 Here are some of the key chemicals used in the electronics industry, along with their roles and applications:

1. Silicon (Si)

   • Role: Primary material for semiconductors

   • Applications: Microchips, integrated circuits, solar cells

2. Gallium Arsenide (GaAs)

   • Role: Semiconductor material with superior electronic properties

   • Applications: High-frequency devices, mobile phones, satellite communications, infrared LEDs

3. Copper (Cu)

   • Role: Conductive material

   • Applications: Wiring, printed circuit boards (PCBs), connectors

4. Silver (Ag)

   • Role: Conductive material with high electrical conductivity

   • Applications: Conductive inks, PCBs, connectors

5. Lead (Pb)

   • Role: Used in soldering

   • Applications: Solder for joining electronic components (Note: Lead-free alternatives are increasingly used due to health concerns)

6. Tin (Sn)

   • Role: Used in soldering

   • Applications: Solder for joining electronic components

7. Gold (Au)

   • Role: Conductive material with excellent corrosion resistance

   • Applications: Connectors, bonding wires, plating for contacts

8. Phosphoric Acid (H₃PO₄)

   • Role: Etching agent

   • Applications: Cleaning and etching of semiconductor wafers

9. Sulfuric Acid (H₂SO₄)

   • Role: Cleaning and etching agent

   • Applications: Cleaning semiconductor wafers, etching PCBs

10. Isopropyl Alcohol (IPA)

    • Role: Cleaning agent

    • Applications: Cleaning electronic components and PCBs

11. Soldering Materials

    • Solder Wire: For hand soldering

    • Solder Paste: Used for surface-mount device (SMD) soldering

    • Solder Bar: For wave soldering and dip soldering

    • Solder Balls: For ball grid array (BGA) packages

    • Flux: Used to clean and prepare surfaces for soldering

12. PCB Chemicals

    • Solder Mask: Protects PCB traces from oxidation and prevents solder bridges

    • Flux Cleaner: Removes flux residues after soldering

    • Degreaser: Cleans PCBs and electronic components

    • Conformal Coating: Protects PCBs from harsh environments

    • Heat-Sink Compound: Enhances heat dissipation from electronic components

13. ESD Protection Materials

    • ESD Mat: Prevents electrostatic discharge damage

    • ESD Clothing: Protects against electrostatic discharge

    • Grounding Material: Ensures proper grounding to prevent static buildup

These chemicals play crucial roles in various stages of electronics manufacturing, from semiconductor fabrication to final assembly, ensuring the performance and reliability of electronic devices

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.016

 

1. Calcium (Ca)

   • Role: Essential for bone and teeth formation, muscle contraction, nerve transmission, and blood clotting.

   • Sources: Dairy products, leafy green vegetables, almonds, and fortified foods.

2. Iron (Fe)

   • Role: Critical for the production of hemoglobin, which carries oxygen in the blood, and myoglobin in muscles.

   • Sources: Red meat, poultry, fish, beans, lentils, spinach, and fortified cereals.

3. Magnesium (Mg)

   • Role: Involved in over 300 biochemical reactions, including muscle and nerve function, blood glucose control, and bone health.

   • Sources: Nuts, seeds, whole grains, green leafy vegetables, and legumes.

4. Potassium (K)

   • Role: Maintains proper fluid balance, nerve transmission, and muscle contraction.

   • Sources: Bananas, oranges, potatoes, spinach, and beans.

5. Zinc (Zn)

   • Role: Supports immune function, wound healing, DNA synthesis, and cell division.

   • Sources: Meat, shellfish, legumes, seeds, nuts, and dairy products.

6. Phosphorus (P)

   • Role: Important for the formation of bones and teeth, and plays a role in the body's energy production and storage.

   • Sources: Meat, dairy products, nuts, seeds, and whole grains.

7. Iodine (I)

   • Role: Essential for the production of thyroid hormones, which regulate metabolism.

   • Sources: Iodized salt, seafood, dairy products, and eggs.

8. Selenium (Se)

   • Role: Acts as an antioxidant, supports immune function, and thyroid hormone metabolism.

   • Sources: Brazil nuts, seafood, meat, eggs, and whole grains.

9. Copper (Cu)

   • Role: Involved in iron metabolism, energy production, and the formation of connective tissue and neurotransmitters.

   • Sources: Shellfish, nuts, seeds, whole grains, and chocolate.

10. Manganese (Mn)

    • Role: Involved in bone formation, blood clotting, and reducing inflammation.

    • Sources: Nuts, seeds, whole grains, leafy green vegetables, and tea.

11. Chromium (Cr)

    • Role: Enhances the action of insulin and is involved in carbohydrate, fat, and protein metabolism.

    • Sources: Meat, whole grains, fruits, vegetables, and nuts.

12. Molybdenum (Mo)

    • Role: Acts as a cofactor for enzymes involved in the metabolism of sulfur-containing amino acids and purines.

    • Sources: Legumes, grains, nuts, and leafy vegetables.

13. Fluoride (F)

    • Role: Essential for the formation of strong teeth and bones, and helps prevent dental cavities.

    • Sources: Fluoridated water, tea, seafood, and certain dental products.

These minerals are vital for various bodily functions, including maintaining bone health, supporting the immune system, producing energy, and ensuring proper muscle and nerve function. A balanced diet that includes a variety of nutrient-rich foods can help ensure adequate intake of these essential minerals.

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.015

 

1. Alanine (Ala)

   • Role: Involved in the metabolism of glucose, supports immune system function.

   • Sources: Meat, poultry, fish, eggs, dairy, legumes

2. Arginine (Arg)

   • Role: Supports the production of nitric oxide, improves circulation, aids in wound healing.

   • Sources: Meat, poultry, fish, dairy, nuts, seeds

3. Asparagine (Asn)

   • Role: Helps with ammonia detoxification and protein synthesis.

   • Sources: Meat, poultry, fish, eggs, dairy, asparagus

4. Aspartic Acid (Asp)

   • Role: Participates in the urea cycle and energy production.

   • Sources: Meat, poultry, fish, eggs, dairy, nuts, seeds

5. Cysteine (Cys)

   • Role: Important for protein structure, acts as an antioxidant.

   • Sources: Meat, poultry, fish, eggs, dairy, garlic, onions

6. Glutamic Acid (Glu)

   • Role: Acts as an excitatory neurotransmitter, involved in protein synthesis.

   • Sources: Meat, poultry, fish, eggs, dairy, soy products

7. Glutamine (Gln)

   • Role: Supports immune system function, aids in gut health.

   • Sources: Meat, poultry, fish, eggs, dairy, beans, spinach

8. Glycine (Gly)

   • Role: Involved in collagen formation, aids in detoxification.

   • Sources: Meat, poultry, fish, eggs, dairy, gelatin

9. Histidine (His)

   • Role: Precursor to histamine, important for immune response and digestion.

   • Sources: Meat, poultry, fish, dairy, grains

10. Isoleucine (Ile)

    • Role: Helps with muscle repair and growth, regulates blood sugar.

    • Sources: Meat, poultry, fish, eggs, dairy, legumes

11. Leucine (Leu)

    • Role: Stimulates muscle protein synthesis, provides energy during exercise.

    • Sources: Meat, poultry, fish, eggs, dairy, legumes

12. Lysine (Lys)

    • Role: Important for collagen formation, aids in calcium absorption.

    • Sources: Meat, poultry, fish, eggs, dairy, legumes

13. Methionine (Met)

    • Role: Acts as a precursor to other amino acids, involved in detoxification.

    • Sources: Meat, poultry, fish, eggs, dairy, nuts, seeds

14. Phenylalanine (Phe)

    • Role: Precursor to neurotransmitters like dopamine and norepinephrine.

    • Sources: Meat, poultry, fish, eggs, dairy, soy products

15. Proline (Pro)

    • Role: Important for collagen production, aids in skin health.

    • Sources: Meat, poultry, fish, eggs, dairy, gelatin

16. Serine (Ser)

    • Role: Involved in the metabolism of fats and immune system function.

    • Sources: Meat, poultry, fish, eggs, dairy, soy products

17. Threonine (Thr)

    • Role: Important for collagen and elastin production, supports immune function.

    • Sources: Meat, poultry, fish, eggs, dairy, nuts, seeds

18. Tryptophan (Trp)

    • Role: Precursor to serotonin, aids in sleep and mood regulation.

    • Sources: Meat, poultry, fish, eggs, dairy, nuts, seeds

19. Tyrosine (Tyr)

    • Role: Precursor to neurotransmitters like dopamine and norepinephrine.

    • Sources: Meat, poultry, fish, eggs, dairy, soy products

20. Valine (Val)

    • Role: Helps with muscle repair and growth, provides energy during exercise.

    • Sources: Meat, poultry, fish, eggs, dairy, legumes

These amino acids are essential for various bodily functions, including muscle repair, immune function, neurotransmitter production, and more. Some are classified as essential amino acids, meaning they must be obtained through diet, while others are non-essential and can be synthesized by the body.

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.014

 Chemical Composition and Properties:

• Formula: CH₃COOH

• Molecular Weight: 60.05 g/mol

• Appearance: Colorless liquid with a pungent, vinegar-like odor

• Solubility: Highly soluble in water, ethanol, and many other organic solvents

• Density: 1.049 g/cm³

• Boiling Point: 118.1°C (244.6°F)

• Melting Point: 16.7°C (62.1°F)

Natural Occurrence:

• Found naturally in various fruits and plants

• Produced by the fermentation of ethanol by acetic acid bacteria

Industrial Production:

• Synthetic Methods: Produced via the methanol carbonylation process, which involves reacting methanol with carbon monoxide

• Biological Methods: Produced by the fermentation of ethanol or sugars by acetic acid bacteria, commonly used in vinegar production

Uses:

• Food Industry: Used as a food preservative, flavoring agent, and acidity regulator (E260). It's the main component of vinegar.

• Chemical Industry: Used in the production of various chemicals like vinyl acetate monomer (used in making adhesives), acetic anhydride, and acetate esters

• Textile Industry: Employed in the dyeing and finishing of textiles

• Pharmaceuticals: Used in the production of drugs and pharmaceuticals, including aspirin

• Household: Commonly used as a cleaning agent and in descaling solutions

• Agriculture: Used in the formulation of herbicides and fungicides

Reactions:

• With Bases: Reacts with bases to form acetate salts, e.g., CH₃COOH + NaOH → CH₃COONa + H₂O

• With Alcohols: Reacts with alcohols to form esters, e.g., CH₃COOH + CH₃OH → CH₃COOCH₃ + H₂O (methyl acetate)

• With Metals: Reacts with certain metals to form hydrogen gas and metal acetates, e.g., 2CH₃COOH + Mg → (CH₃COO)₂Mg + H₂

Health and Safety:

• Inhalation: Vapors can cause respiratory irritation

• Ingestion: Can cause digestive tract irritation and discomfort; concentrated acetic acid is corrosive and can cause severe burns

• Skin Contact: Can cause irritation and burns, particularly with concentrated solutions

• Eye Contact: Can cause severe irritation and damage; safety precautions, such as wearing protective eyewear and gloves, are recommended when handling concentrated acetic acid

Environmental Impact:

• Generally considered biodegradable and not environmentally persistent

• Large spills or improper disposal can lead to environmental harm, particularly to aquatic life due to acidity

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.013

 Chemical Composition and Properties:

• Formula: MgSO₄

• Molecular Weight: 120.37 g/mol

• Appearance: Colorless or white crystalline solid

• Solubility: Soluble in water, slightly soluble in alcohol and glycerin

Forms:

• Anhydrous: MgSO₄ (anhydrous)

• Heptahydrate: MgSO₄·7H₂O, commonly known as Epsom salt

Natural Occurrence:

• Found in mineral deposits like epsomite, kieserite, and langbeinite

• Common in saline environments, such as salt lakes and underground deposits

Industrial Uses:

• Agriculture: Used as a fertilizer to correct magnesium or sulfur deficiencies in soil, promotes plant growth

• Medicine: Used in Epsom salt baths to relieve muscle soreness, as a laxative, and to treat magnesium deficiency

• Food Industry: Used as a coagulant in the preparation of tofu

• Chemicals: Used in the manufacture of textiles, paper, and in the tanning industry

• Water Treatment: Employed to improve the clarity and quality of water

• Construction: Used in cement and as a fireproofing material

Biological Role:

• Magnesium sulfate plays a vital role in various biological processes

• Enzyme Reactions: Acts as a cofactor in over 300 enzymatic reactions, including protein synthesis, muscle and nerve function, and blood glucose control

• Electrolyte Balance: Helps maintain electrolyte balance in the body

Reactions:

• With Water: Dissolves to form magnesium ions (Mg²⁺) and sulfate ions (SO₄²⁻)

• With Acids: Reacts with acids to form magnesium salts and sulfuric acid

• Thermal Decomposition: Decomposes at high temperatures to form magnesium oxide (MgO) and sulfur trioxide (SO₃)

Health and Safety:

• Inhalation: Dust can irritate the respiratory tract

• Ingestion: Generally considered safe when used appropriately, excessive intake can lead to hypermagnesemia (high levels of magnesium in the blood)

• Skin Contact: May cause minor irritation, Epsom salt baths are generally safe for topical use

Environmental Impact:

• Generally considered safe for the environment when used in appropriate quantities

• Excessive use as a fertilizer can contribute to water pollution through runoff

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.012

 Chemical Composition and Properties:

• Formula: CaCO₃

• Molecular Weight: 100.09 g/mol

• Appearance: White, odorless powder or colorless crystals

Natural Occurrence:

• Minerals: Found in minerals like calcite, aragonite, and vaterite

• Sedimentary Rocks: Main component of limestone and marble

• Biological Role: Present in the shells of marine organisms, snails, pearls, and eggshells

Industrial Uses:

• Construction: Used as a building material (marble), aggregate (limestone), and in cement production

• Food Industry: Acts as a calcium supplement, acidity regulator, and an anti-caking agent

• Pharmaceuticals: Used in antacids and as a calcium source

• Paper Production: Acts as a filler and coating pigment

• Plastics: Increases the durability and extends the life of plastic products

• Paints: Serves as a white pigment (also known as whiting)

Reactions:

• With Acids: Reacts with acids to produce carbon dioxide, water, and a dissolved salt, e.g., CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

• Thermal Decomposition: Decomposes to form calcium oxide (quicklime) and carbon dioxide upon heating, e.g., CaCO₃ → CaO + CO₂

Environmental Impact:

• Natural Waterways: Helps neutralize acidic waters and acts as a natural buffering agent

• Acid Rain: Limestone can be used to neutralize the effects of acid rain on lakes and soils

• Carbon Sequestration: Calcium carbonate formation helps in capturing carbon dioxide from the atmosphere

Health and Safety:

• Inhalation: Dust can irritate the respiratory tract

• Ingestion: Generally considered safe, but excessive intake can lead to hypercalcemia (high levels of calcium in the blood)

• Skin Contact: May cause minor irritation

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.011

 

Chemical Properties

• Formula: AgNO₂

• Molar Mass: 153.87 g/mol

• Appearance: Colorless to yellow crystals

• Odor: Odorless

• Density: 4.453 g/cm³ at 25°C

• Melting Point: 140°C (284°F)

• Solubility: Soluble in hot water, insoluble in ethanol

• Magnetic Susceptibility: -42.0·10⁻⁶ cm³/mol

Structure

Silver nitrite has a crystalline structure with silver ions (Ag⁺) and nitrite ions (NO₂⁻). The nitrite ion has a bent molecular geometry with an O-N-O bond angle of approximately 115°.

Preparation

Silver nitrite can be prepared through the reaction of silver nitrate (AgNO₃) with an alkali nitrite, such as sodium nitrite (NaNO₂). The reaction is as follows:

$${\text{<span style="font-family: Diphylleia;">AgNO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">(</span>\mathrm{<span\; style="font-family:\; Diphylleia;">a</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">q</span>}<span\; style="font-family:\; Diphylleia;">)</span><span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">NaNO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">(</span>\mathrm{<span\; style="font-family:\; Diphylleia;">s</span>}<span\; style="font-family:\; Diphylleia;">)</span><span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">NaNO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">(</span>\mathrm{<span\; style="font-family:\; Diphylleia;">a</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">q</span>}<span\; style="font-family:\; Diphylleia;">)</span><span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">AgNO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">(</span>\mathrm{<span\; style="font-family:\; Diphylleia;">p</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">r</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">e</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">c</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">i</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">p</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">i</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">t</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">a</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">t</span>}\mathrm{<span\; style="font-family:\; Diphylleia;">e</span>}<span\; style="font-family:\; Diphylleia;">)</span>\backslash text\{AgNO\}\_3\; (aq)\; +\; \backslash text\{NaNO\}\_2\; (s)\; \backslash rightarrow\; \backslash text\{NaNO\}\_3\; (aq)\; +\; \backslash text\{AgNO\}\_2\; (precipitate)$$

Alternatively, it can be produced by the reaction between silver sulfate (Ag₂SO₄) and barium nitrite (Ba(NO₂)₂).

Uses

• Oxidizing Agent: Silver nitrite is used as a general oxidizing agent in various chemical reactions.

• Production of Aniline Compounds: It is used in the synthesis of aniline compounds.

• Nucleophilic Substitution Reactions: Employed in Victor Meyer type nucleophilic substitution reactions with organobromides or organoiodides to form nitro compounds.

• Nitroalkene Synthesis: Used in the synthesis of nitroalkenes with nitryl iodide generated in-situ from silver nitrite and elemental iodine.

• Skeletal Editing: Involved in the synthesis of 1,2,3-benzothiadiazoles via skeletal editing (S,N-heteroarene ring transformation) of variously functionalized 2-halobenzothiazoles and benzothiazolinones.

Safety and Hazards

• Hazard Statements: H272 (May intensify fire; oxidizer), H302 (Harmful if swallowed), H315 (Causes skin irritation), H319 (Causes serious eye irritation), H400 (Very toxic to aquatic life)

• Precautionary Statements: P210 (Keep away from heat/sparks/open flames/hot surfaces. No smoking), P220 (Keep/Store away from clothing/combustible materials), P221 (Take any precaution to avoid mixing with combustibles), P264 (Wash hands thoroughly after handling), P270 (Do not eat, drink or smoke when using this product), P273 (Avoid release to the environment), P280 (Wear protective gloves/protective clothing/eye protection/face protection), P301+P312 (IF SWALLOWED: Call a POISON CENTER or doctor/physician if you feel unwell), P302+P352 (IF ON SKIN: Wash with plenty of soap and water), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing), P321 (Specific treatment), P330 (Rinse mouth), P332+P313 (If skin irritation occurs: Get medical advice/attention), P337+P313 (If eye irritation persists: Get medical advice/attention), P362 (Take off contaminated clothing and wash before reuse), P370+P378 (In case of fire: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide for extinction), P391 (Collect spillage), P501 (Dispose of contents/container in accordance with local/regional/national/international regulations)

• NFPA 704 (Fire Diamond): 2 (Health), 0 (Flammability), 2 (Reactivity)

• Lethal Dose (LD50): Not available

Environmental Impact

Silver nitrite is very toxic to aquatic life and should be handled with care to prevent environmental contamination. Proper disposal methods should be followed to minimize its impact on the environment.

Handling and Storage

• Handling: Use in well-ventilated areas; avoid inhalation and contact with skin and eyes; use appropriate personal protective equipment (PPE).

• Storage: Store in tightly sealed containers made of corrosion-resistant materials; keep away from incompatible substances such as bases and oxidizers.

Industrial Applications

• Silver Plating: Used in the silver plating process.

• Hair Dye: Employed in the formulation of hair dyes.

• Inks and Markers: Used in the production of inks and permanent marker pens.

• Water Analysis: Used for the preparation of standard sodium nitrite solutions for water analysis.

• Reagent: Used as a reagent for primary, secondary, and tertiary alcohols.

Chemical Reactions

• Reaction with Acids: Silver nitrite reacts with acids to form silver salts and nitrous acid (HNO₂).

• Reaction with Halides: Reacts with halides to form silver halides and nitrite ions.

Historical Background

Silver nitrite has been used in various chemical reactions and industrial applications for many years. Its unique properties as an oxidizing agent and its ability to participate in nucleophilic substitution reactions have made it a valuable compound in organic synthesis.

Molecular and Crystal Structure

The crystal structure of silver nitrite consists of silver ions (Ag⁺) and nitrite ions (NO₂⁻) arranged in a lattice. The nitrite ion has a bent molecular geometry with an O-N-O bond angle of approximately 115°.

Detection and Measurement

• Spectroscopy: Silver nitrite can be detected and measured using various spectroscopic techniques, including UV-Vis and IR spectroscopy.

• Titration: It can also be quantified using titration methods with appropriate indicators.

Purification

Silver nitrite can be purified by crystallization from hot conductivity water in the dark. It should be dried in the dark under vacuum to prevent decomposition.

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.010

 

Chemical Properties

• Formula: H₂SO₄

• Molar Mass: 98.079 g/mol

• Appearance: Colorless, odorless, and viscous liquid

• Density: 1.8302 g/cm³ (liquid)

• Melting Point: 10.31°C (50.56°F)

• Boiling Point: 337°C (639°F)

• Solubility: Miscible with water, exothermic reaction

• Acidity (pKa): pKa1 = -2.8, pKa2 = 1.99

• Conjugate Base: Bisulfate (HSO₄⁻)

• Viscosity: 26.7 cP (20°C)

• Vapor Pressure: 0.001 mmHg (20°C)

Structure

Sulfuric acid has a tetrahedral molecular geometry with a central sulfur atom bonded to four oxygen atoms. The bond lengths are approximately 142.2 pm for S=O and 157.4 pm for S-O. The O-H bond length is 97 pm.

Preparation

• Contact Process: The most common industrial method for producing sulfuric acid. It involves the catalytic oxidation of sulfur dioxide (SO₂) to sulfur trioxide (SO₃), which is then absorbed in water to form sulfuric acid:

$${\text{<span style="font-family: Diphylleia;">SO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">O</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">SO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}\backslash text\{SO\}\_2\; +\; \backslash text\{O\}\_2\; \backslash rightarrow\; \backslash text\{SO\}\_3$$

$${\text{<span style="font-family: Diphylleia;">SO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}{\text{<span style="font-family: Diphylleia;">SO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}}\backslash text\{SO\}\_3\; +\; \backslash text\{H\}\_2\backslash text\{O\}\; \backslash rightarrow\; \backslash text\{H\}\_2\backslash text\{SO\}\_4$$

• Chamber Process: An older method that has largely been replaced by the contact process. It involves the oxidation of sulfur dioxide in the presence of nitrogen oxides as catalysts.

Uses

• Fertilizers: Sulfuric acid is widely used in the production of phosphate fertilizers, such as superphosphate and ammonium sulfate.

• Chemical Manufacturing: Used in the production of various chemicals, including hydrochloric acid, nitric acid, sulfate salts, synthetic detergents, dyes, pigments, explosives, and pharmaceuticals.

• Petroleum Refining: Employed in the refining of petroleum to remove impurities.

• Metal Processing: Used in the pickling of metals to remove rust and scale.

• Batteries: Serves as the electrolyte in lead-acid storage batteries.

• Cleaning Agent: Used as a cleaning agent in industries to remove rust from steel and iron.

• Catalyst: Acts as a catalyst in various chemical reactions, such as the conversion of cyclohexanone oxime to caprolactam for nylon production.

Safety and Hazards

• Hazard Statements: H314 (Causes severe skin burns and eye damage)

• Precautionary Statements: P260 (Do not breathe dust/fume/gas/mist/vapors/spray), P264 (Wash thoroughly after handling), P280 (Wear protective gloves/protective clothing/eye protection/face protection), P301+P330+P331 (IF SWALLOWED: Rinse mouth. Do NOT induce vomiting), P303+P361+P353 (IF ON SKIN (or hair): Remove/take off immediately all contaminated clothing. Rinse skin with water/shower), P304+P340 (IF INHALED: Remove person to fresh air and keep comfortable for breathing), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing), P310 (Immediately call a POISON CENTER or doctor/physician), P321 (Specific treatment), P363 (Wash contaminated clothing before reuse), P405 (Store locked up), P501 (Dispose of contents/container in accordance with local/regional/national/international regulations)

• NFPA 704 (Fire Diamond): 3 (Health), 0 (Flammability), 2 (Reactivity), W (Water-reactive), OX (Oxidizer)

• Lethal Dose (LD50): 2140 mg/kg (rat, oral)

Environmental Impact

Sulfuric acid is a significant environmental pollutant and can contribute to acid rain. It is highly corrosive and can cause severe damage to aquatic life and vegetation. Proper handling and disposal are essential to minimize its environmental impact.

Handling and Storage

• Handling: Use in well-ventilated areas; avoid inhalation and contact with skin and eyes; use appropriate personal protective equipment (PPE).

• Storage: Store in tightly sealed containers made of corrosion-resistant materials; keep away from incompatible substances such as bases and oxidizers.

Historical Background

Sulfuric acid, also known as oil of vitriol, has been known

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.009

 

Chemical Properties

• Formula: H₃BO₃

• Molar Mass: 61.83 g/mol

• Appearance: White crystalline solid or powder

• Odor: Odorless

• Density: 1.435 g/cm³

• Melting Point: 170.9°C (339.6°F)

• Boiling Point: 300°C (572°F)

• Solubility: Soluble in water, lower alcohols, moderately soluble in pyridine, very slightly soluble in acetone

• Acidity (pKa): 9.24 (first proton), 12.4 (second), 13.3 (complete)

• Conjugate Base: Borate

• Magnetic Susceptibility: -34.1·10⁻⁶ cm³/mol

Structure

Boric acid has a trigonal planar molecular geometry with three oxygen atoms forming a planar structure around the boron atom. The bond lengths are approximately 136 pm for B-O and 97 pm for O-H. The dipole moment is 0 D, indicating a non-polar molecule.

Preparation

• From Borax: Boric acid can be prepared by reacting borax (sodium tetraborate) with a mineral acid such as hydrochloric acid:

$${\text{<span style="font-family: Diphylleia;">Na</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}{\text{<span style="font-family: Diphylleia;">B</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}}{\text{<span style="font-family: Diphylleia;">O</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">7</span>}}<span\; style="font-family:\; Diphylleia;">\cdot </span>\mathrm{<span\; style="font-family:\; Diphylleia;">10</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}\text{<span style="font-family: Diphylleia;">HCl</span>}<span\; style="font-family:\; Diphylleia;">\to </span>\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}{\text{<span style="font-family: Diphylleia;">BO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">5</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}\text{<span style="font-family: Diphylleia;">NaCl</span>}\backslash text\{Na\}\_2\backslash text\{B\}\_4\backslash text\{O\}\_7\; \backslash cdot\; 10\backslash text\{H\}\_2\backslash text\{O\}\; +\; 2\backslash text\{HCl\}\; \backslash rightarrow\; 4\backslash text\{H\}\_3\backslash text\{BO\}\_3\; +\; 5\backslash text\{H\}\_2\backslash text\{O\}\; +\; 2\backslash text\{NaCl\}$$

• From Hydrolysis of Diborane: Boric acid can also be prepared from the hydrolysis of diborane (B₂H₆):

$${\text{<span style="font-family: Diphylleia;">B</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">6</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">6</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">\to </span>\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}{\text{<span style="font-family: Diphylleia;">BO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">6</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\backslash text\{B\}\_2\backslash text\{H\}\_6\; +\; 6\backslash text\{H\}\_2\backslash text\{O\}\; \backslash rightarrow\; 2\backslash text\{H\}\_3\backslash text\{BO\}\_3\; +\; 6\backslash text\{H\}\_2$$

• From Hydrolysis of Boron Trihalides: Boric acid can be formed as a by-product of the hydrolysis of boron trihalides (BX₃):

$${\text{<span style="font-family: Diphylleia;">BX</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}{\text{<span style="font-family: Diphylleia;">BO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}\text{<span style="font-family: Diphylleia;">HX</span>}\backslash text\{BX\}\_3\; +\; 3\backslash text\{H\}\_2\backslash text\{O\}\; \backslash rightarrow\; \backslash text\{H\}\_3\backslash text\{BO\}\_3\; +\; 3\backslash text\{HX\}$$

Uses

• Antiseptic: Boric acid is widely used as an antiseptic for minor cuts and burns. It is also used in medical dressings and salves.

• Insecticide: It is used as an insecticide to control pests such as ants, cockroaches, and termites.

• Flame Retardant: Boric acid is used as a flame retardant in various materials, including textiles and plastics.

• Neutron Absorber: It is used in nuclear power plants as a neutron absorber to control the rate of fission.

• Eyewash: Very dilute solutions of boric acid can be used as an eyewash to treat minor eye infections.

• Acne Treatment: Due to its antibacterial properties, boric acid can be used to treat acne.

• Athlete's Foot: In its powdered form, boric acid can be sprinkled into socks and shoes to prevent athlete's foot (tinea pedis).

Safety and Hazards

• Hazard Statements: H360FD (May damage fertility or the unborn child), H319 (Causes serious eye irritation)

• Precautionary Statements: P201 (Obtain special instructions before use), P280 (Wear protective gloves/protective clothing/eye protection/face protection), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing), P308+P313 (IF exposed or concerned: Get medical advice/attention)

• NFPA 704 (Fire Diamond): 1 (Health), 0 (Flammability), 0 (Reactivity)

• Lethal Dose (LD50): 2660 mg/kg (oral, rat)

Environmental Impact

Boric acid is not biodegradable but is generally considered safe for the environment when used appropriately. However, it can be toxic to plants and aquatic life in high concentrations.

Handling and Storage

• Handling: Use in well-ventilated areas; avoid inhalation and contact with skin and eyes; use appropriate personal protective equipment (PPE).

• Storage: Store in tightly sealed containers made of corrosion-resistant materials; keep away from incompatible substances such as bases and oxidizers.

Historical Background

Boric acid was first prepared by Wilhelm Homberg in the early 18th century from borax by the action of mineral acids. It was initially named "sal sedativum Hombergi" (sedative salt of Homberg). Boric acid and borates have been used since ancient times for cleaning, preserving food, and other activities.

Molecular and Crystal Structure

The three oxygen atoms form a trigonal planar geometry around the boron atom. The bond lengths are approximately 136 pm for B-O and 97 pm for O-H. The structure of the unit cell of boric acid is trigonal planar.

Chemical Reactions

• Dehydration: On heating, boric acid undergoes dehydration to form metaboric acid (HBO₂) and tetraboric acid (H₂B₄O₇):

$${\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}{\text{<span style="font-family: Diphylleia;">BO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">HBO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}\backslash text\{H\}\_3\backslash text\{BO\}\_3\; \backslash rightarrow\; \backslash text\{HBO\}\_2\; +\; \backslash text\{H\}\_2\backslash text\{O\}$$

$$\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}{\text{<span style="font-family: Diphylleia;">HBO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}{\text{<span style="font-family: Diphylleia;">B</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}}{\text{<span style="font-family: Diphylleia;">O</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">7</span>}}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}4\backslash text\{HBO\}\_2\; \backslash rightarrow\; \backslash text\{H\}\_2\backslash text\{B\}\_4\backslash text\{O\}\_7\; +\; \backslash text\{H\}\_2\backslash text\{O\}$$

• Reaction with Alcohols: Boric acid reacts with alcohols to form borate esters:

$${\text{<span style="font-family: Diphylleia;">B(OH)</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}\text{<span style="font-family: Diphylleia;">ROH</span>}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">B(OR)</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}\backslash text\{B(OH)\}\_3\; +\; 3\backslash text\{ROH\}\; \backslash rightarrow\; \backslash text\{B(OR)\}\_3\; +\; 3\backslash text\{H\}\_2\backslash text\{O\}$$

• Reaction with Anhydrous Sulfuric Acid: Boric acid dissolves in anhydrous sulfuric acid:

$${\text{<span style="font-family: Diphylleia;">B(OH)</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">6</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}{\text{<span style="font-family: Diphylleia;">SO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">B(HSO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}}{\text{<span style="font-family: Diphylleia;">)</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}}^{<span\; style="font-family:\; Diphylleia;">-</span>}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}{\text{<span style="font-family: Diphylleia;">HSO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}}^{<span\; style="font-family:\; Diphylleia;">-</span>}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}{\text{<span style="font-family: Diphylleia;">O</span>}}^{<span\; style="font-family:\; Diphylleia;">+</span>}\backslash text\{B(OH)\}\_3\; +\; 6\backslash text\{H\}\_2\backslash text\{SO\}\_4\; \backslash rightarrow\; \backslash text\{B(HSO\}\_4\backslash text\{)\}\_4^-\; +\; 2\backslash text\{HSO\}\_4^-\; +\; 3\backslash text\{H\}\_3\backslash text\{O\}^+$$

Industrial Applications

• Glass and Ceramics: Used in the production of borosilicate glass and ceramics.

• Fiberglass: Used in the manufacturing of monofilament fiberglass.

• Adhesives and Sealants: Used in the formulation of adhesives and sealants.

• Electronics: Used in the production of electronic components and semiconductors

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.008

 

Chemical Properties

• Formula: CH₂O

• Molar Mass: 30.03 g/mol

• Appearance: Colorless gas or aqueous solution

• Odor: Pungent, irritating odor

• Density: 1.09 g/cm³ (gas), 1.08 g/cm³ (aqueous solution, 37%)

• Melting Point: -92°C (-134°F)

• Boiling Point: -19°C (-2°F) (gas), varies with concentration for the aqueous solution

• Solubility: Highly soluble in water, forming formalin; also soluble in alcohols and other polar solvents

Physical Properties

• State: Gas at standard temperature and pressure (STP), but commonly used as an aqueous solution (formalin)

• Structure: Simple aldehyde with a carbonyl group (C=O) bonded to two hydrogen atoms

Preparation

• Laboratory Method: Produced by the catalytic oxidation of methanol (CH₃OH) using a silver or copper catalyst:

$${\text{<span style="font-family: Diphylleia;">CH</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}\text{<span style="font-family: Diphylleia;">OH</span>}<span\; style="font-family:\; Diphylleia;">+</span>\frac{\mathrm{<span\; style="font-family:\; Diphylleia;">1</span>}}{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}{\text{<span style="font-family: Diphylleia;">O</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">CH</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}\backslash text\{CH\}\_3\backslash text\{OH\}\; +\; \backslash frac\{1\}\{2\}\; \backslash text\{O\}\_2\; \backslash rightarrow\; \backslash text\{CH\}\_2\backslash text\{O\}\; +\; \backslash text\{H\}\_2\backslash text\{O\}$$

• Industrial Method: Produced by the oxidation of methanol in the presence of a metal oxide catalyst, such as iron oxide or molybdenum oxide.

Uses

• Chemical Industry: Used in the production of various chemicals, such as urea-formaldehyde resins, phenol-formaldehyde resins, and polyacetal resins.

• Laboratory Reagent: Used in analytical chemistry and various laboratory processes.

• Medical: Used as a disinfectant, preservative, and in the preparation of vaccines.

• Textile Industry: Used in the treatment of fabrics to make them wrinkle-resistant.

• Construction: Used in the production of plywood, particleboard, and other building materials.

Safety and Hazards

• Hazard Statements: H301 (Toxic if swallowed), H311 (Toxic in contact with skin), H331 (Toxic if inhaled), H314 (Causes severe skin burns and eye damage), H317 (May cause an allergic skin reaction), H350 (May cause cancer)

• Precautionary Statements: P201 (Obtain special instructions before use), P280 (Wear protective gloves/protective clothing/eye protection/face protection), P301+P310 (IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing), P308+P313 (IF exposed or concerned: Get medical advice/attention)

• NFPA 704 (Fire Diamond): 3 (Health), 2 (Flammability), 0 (Reactivity)

• Lethal Dose (LD50): 100 mg/kg (rat, oral)

Environmental Impact

• Air Pollution: Formaldehyde is a significant air pollutant and can contribute to the formation of ground-level ozone and smog.

• Water Pollution: Formaldehyde can contaminate water sources and pose a risk to aquatic life.

Handling and Storage

• Handling: Use in well-ventilated areas; avoid inhalation and contact with skin and eyes; use appropriate personal protective equipment (PPE).

• Storage: Store in tightly sealed containers made of corrosion-resistant materials; keep away from incompatible substances such as bases and oxidizers.

Health Effects

• Inhalation: Can cause sore throat, coughing, shortness of breath, and respiratory irritation.

• Skin Contact: May cause irritation, redness, and burns.

• Eye Contact: Causes severe eye irritation and damage.

• Ingestion: Can cause gastrointestinal irritation, nausea, vomiting, and potentially fatal poisoning.

Detection and Measurement

• Odorization: Formaldehyde has a distinct, pungent odor that can be detected at low concentrations.

• Sensors: Formaldehyde detectors and sensors are used in various industries to monitor and prevent leaks and ensure safety.

Chemical Reactions

• Combustion: Formaldehyde undergoes complete combustion in the presence of oxygen to produce carbon dioxide and water vapor:

$${\text{<span style="font-family: Diphylleia;">CH</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">O</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">\to </span>{\text{<span style="font-family: Diphylleia;">CO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}\backslash text\{CH\}\_2\backslash text\{O\}\; +\; \backslash text\{O\}\_2\; \backslash rightarrow\; \backslash text\{CO\}\_2\; +\; \backslash text\{H\}\_2\backslash text\{O\}$$

• Polymerization: Formaldehyde can polymerize to form paraformaldehyde, a solid polymer used in various applications.

Industrial Applications

• Resin Production: Used in the production of urea-formaldehyde resins, phenol-formaldehyde resins, and melamine-formaldehyde resins.

• Disinfectants: Used as a disinfectant and preservative in medical and laboratory settings.

• Textile Treatment: Used to treat fabrics to make them wrinkle-resistant and durable.

• Construction Materials: Used in the production of plywood, particleboard, and other building materials.

கொஞ்சம் கெமிஸ்ட்ரி ! - EP.007

 

Chemical Properties

• Formula: CH₃COCH₃

• Molar Mass: 58.08 g/mol

• Appearance: Colorless liquid

• Odor: Pungent, fruity

• Density: 0.7845 g/cm³ (25°C)

• Melting Point: -94.9°C (-138.8°F)

• Boiling Point: 56.08°C (132.94°F)

• Solubility: Miscible in water, benzene, diethyl ether, methanol, chloroform, ethanol

• Refractive Index: 1.3588 (20°C)

• Viscosity: 0.306 mPa·s (25°C)

• Dipole Moment: 2.88 D

Structure

Acetone has a trigonal planar molecular geometry at the central carbon atom (C2) with a dihedral shape. The carbonyl group (C=O) makes it highly polar.

Preparation

• Industrial Method: Acetone is primarily produced by the cumene process, where benzene is alkylated with propylene to produce cumene, which is then oxidized by air to produce phenol and acetone.

• Laboratory Method: Acetone can be produced by the dry distillation of metal acetates.

Uses

• Solvent: Widely used as a solvent for synthetic fibers, plastics, and in the preparation of metal before painting.

• Chemical Intermediate: Used in the production of methyl methacrylate and bisphenol A.

• Medical: Used as an antiseptic and in pharmaceutical industries.

• Cosmetics: Commonly used in nail polish removers and other cosmetic products.

• Laboratory: Used as a drying agent and to rinse lab glassware.

• Industrial: Employed in the defatting process and in the treatment of acne.

Safety and Hazards

• Main Hazards: Highly flammable, causes serious eye irritation, and may cause respiratory irritation.

• Hazard Statements: H225 (Highly flammable liquid and vapor), H302 (Harmful if swallowed), H319 (Causes serious eye irritation), H336 (May cause drowsiness or dizziness), H373 (May cause damage to organs through prolonged or repeated exposure).

• Precautionary Statements: P210 (Keep away from heat/sparks/open flames/hot surfaces. No smoking), P235 (Keep cool), P260 (Do not breathe dust/fume/gas/mist/vapors/spray), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing).

• NFPA 704 (Fire Diamond): 1 (Health), 3 (Flammability), 0 (Reactivity).

• Flash Point: -20°C (-4°F).

• Autoignition Temperature: 465°C (869°F).

• Explosive Limits: 2.5–12.8%.

• Lethal Dose (LD50): 5800 mg/kg (rat, oral), 3000 mg/kg (mouse, oral), 5340 mg/kg (rabbit, oral).

Environmental Impact

Acetone is not considered a significant environmental hazard, but it should be handled with care to prevent contamination and exposure.

Health Effects

• Inhalation: Can cause sore throat, cough, headaches, dizziness, confusion, faster pulse, nausea, vomiting, and possible coma.

• Skin Contact: May cause irritation and dryness.

• Eye Contact: Causes serious eye irritation.

• Ingestion: Can cause gastrointestinal irritation, nausea, and vomiting.

Detection and Measurement

• Odorization: Acetone has a distinct, pungent odor that can be detected at low concentrations.

• Sensors: Acetone detectors and sensors are used in various industries to monitor and prevent leaks and ensure safety.

Chemical Reactions

• Combustion: Acetone undergoes complete combustion in the presence of oxygen to produce carbon dioxide and water vapor:

$${\text{<span style="font-family: Diphylleia;">CH</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}{\text{<span style="font-family: Diphylleia;">COCH</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">4</span>}{\text{<span style="font-family: Diphylleia;">O</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">\to </span>\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}{\text{<span style="font-family: Diphylleia;">CO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">+</span>\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}\backslash text\{CH\}\_3\backslash text\{COCH\}\_3\; +\; 4\; \backslash text\{O\}\_2\; \backslash rightarrow\; 3\; \backslash text\{CO\}\_2\; +\; 3\; \backslash text\{H\}\_2\backslash text\{O\}$$

• Keto-Enol Tautomerism: Acetone exhibits keto-enol tautomerism, where it can interconvert between the keto form (CH₃COCH₃) and the enol form (CH₂=C(OH)CH₃).

Industrial Applications

• Plastic and Synthetic Fiber Production: Used as a solvent in the production of various plastics and synthetic fibers.

• Pharmaceuticals: Used in the synthesis of active pharmaceutical ingredients (APIs).

• Cosmetics: Used in the formulation of nail polish removers and other cosmetic products.

• Laboratory: Used as a solvent and drying agent in various laboratory processes.