🧴 Chemistry — Chemistry in Everyday Life
1. Synthetic Materials
CEMENT
- Discovered by Joseph Aspdin (1824) — Portland cement
- Composition: CaO (60-70%), SiO₂ (20-25%), Al₂O₃ (5-10%), Fe₂O₃ (2-3%)
- Raw materials: Limestone (lime), Clay (alumina & silica), Gypsum (reduces setting time)
- Setting: Exothermic process; cooled for 7 days by sprinkling water
- Mortar: Cement + Sand + Water (for plastering)
- Concrete: Cement + Sand + Gravel + Water
- Reinforced concrete: Iron rods embedded in concrete
GLASS
- Supercooled liquid of silicates; amorphous, transparent
- Soda glass: Na₂O·CaO·6SiO₂ (window glass, mirrors, common glassware)
- Hard glass: Potassium + Calcium silicates (acid resistant, lab apparatus)
- Flint glass: Na₂O + PbO + SiO₂ (bulbs, optical instruments)
- Pyrex glass (Borosilicate): Sand + Lime + Borax; heat resistant, lab apparatus
- Crookes glass: Contains CeO₂; cuts UV rays; lenses for spectacles
- Safety glass: Plastic layer between two glass layers; auto windshields
- Optical fibre: Telecommunication, surgical operations
- Annealing: Slow and uniform cooling to prevent brittleness
2. Fertilisers
MACRONUTRIENTS
- N, P, K, Ca, Mg, S — required in large quantities
MICRONUTRIENTS
- Fe, Mn, B, Zn, Cu, Mo, Cl — required in small quantities
NITROGENOUS FERTILISERS
- Ammonium sulphate, Calcium cyanamide, Calcium ammonium nitrate
- Urea: Best fertiliser; 46.6% N; leaves only CO₂ after assimilation
- Nitrolim: Mixture of Ca(CN)₂ and C
PHOSPHATIC & NPK FERTILISERS
- Calcium superphosphate, Nitrophosphate, Triple phosphate
- NPK fertilisers: Mixture of Nitrogenous + Phosphatic + Potash fertilisers
3. Pesticides
TYPES
- Insecticides: Kill insects (DDT, Malathion)
- Fungicides: Control fungi
- Nematicides: Kill eelworms
- Molluscicides: Kill slugs and snails
- Herbicides (Weed killers): 2,4-D, Atrazine, Glyphosate
- Pediculticides: Treat lice (Lindane, Malathion)
- Rodenticides: Kill rodents (Zinc phosphide, Difethalone)
4. Explosives
TYPES
- Primary: Extremely sensitive (Acetone peroxide, Silver azide)
- Secondary: Less sensitive (RDX, TNT)
- Blasting agents: Tertiary (ANFO — Ammonium nitrate + Fuel oil)
IMPORTANT EXPLOSIVES
- Nitroglycerine: Noble's oil; highly unstable liquid
- TNT: Yellow insensitive crystals
- RDX: Cyclotrimethylene trinitramine; very powerful
- C-4: RDX plastic explosive
- Dynamite: Nitroglycerine + Diatomaceous earth
- Gunpowder: KNO₃ + Charcoal + Sulphur
5. Polymers
ADDITION POLYMERS
- Polythene: Ethene polymer; insulation, squeeze bottles, toys
- Teflon: Tetrafluoroethylene polymer; non-stick coatings
- Thermocol (Polystyrene): Packaging, insulation
- Polypropylene: Carpeting, upholstery
- Orlon (Polyacrylonitrile): Wool substitute; carbon fibres for defence (Agni missiles)
CONDENSATION POLYMERS
- Bakelite: Phenol + Formaldehyde; electrical switches, handles
- Melamine-formaldehyde: Unbreakable crockery
- Glyptal: Ethylene glycol + Phthalic acid; paints, lacquers
- Nylon: First fully synthetic fibre (1931); polyamide; stronger than steel wire
- Dacron/Terylene: Ethylene glycol + Terephthalic acid; polyester fibre
- Polyurethanes: Foam for mattresses, cushions, insulation
- Polycarbonates: Bulletproof glass, food processor jars
RUBBER
- Natural rubber: Linear polymer of isoprene (cis-1,4-polyisoprene)
- Vulcanisation: Heating rubber with sulphur; makes it hard, strong, elastic
- Synthetic rubber: Neoprene (oil resistant), Buna-N, Buna-S (SBR — automobile tyres)
6. Soaps and Detergents
SOAPS
- Sodium/Potassium salts of higher fatty acids (oleic, stearic, palmitic)
- Saponification: Oil/Fat + NaOH → Soap + Glycerol
- Toilet soaps: Better fats/oils + colours + perfumes
- Medicated soaps: Contain substances of medical value
- Laundry soaps: Sodium rosinate, sodium silicate, borax, sodium carbonate
DETERGENTS
- Contain sulphonic acid group (-SO₃H) instead of -COOH
- Work in hard water (unlike soaps)
- Anionic: Sodium lauryl sulphate, Sodium dodecyl benzene sulphonate
- Cationic: Cetyl trimethyl ammonium bromide
- Non-ionic: Polyethylene glycol stearate
- Biodegradable: Straight chain hydrocarbons preferred over branched chain
7. Chemicals in Medicine
ANALGESICS (Pain Relievers)
- Non-narcotic: Aspirin (anticoagulant, fever reducer), Paracetamol, Ibuprofen
- Narcotic: Morphine, Heroin, Codeine (post-operative pain, terminal cancer)
ANTIBIOTICS
- Penicillin: Discovered by Alexander Fleming (1929)
- Broad spectrum: Ampicillin, Amoxycillin, Chloramphenicol, Sulphadrugs
- Paul Ehrlich: Nobel 1908 for Salvarsan (syphilis)
OTHER MEDICINES
- Antiseptics: Dettol (chloroxylenol + terpineol), Tincture of iodine, Boric acid
- Disinfectants: 1% phenol, 0.2-0.4 ppm chlorine
- Antacids: Mg(OH)₂, Al(OH)₃, NaHCO₃
- Antihistamines: Cimetidine, Ranitidine (Zantac)
- Tranquillisers: Equanil, Luminal (barbiturates), Serpasil (Rauwolfia serpentina)
- Anaesthetics: Propofol, Barbiturates, Benzodiazepine
- Antifertility drugs: Norethindrone, Ethynylestradiol (birth control pills)
8. Chemicals in Food
FOOD ADDITIVES
- Food colours, flavours, sweeteners, preservatives, antioxidants
- Artificial sweeteners: Saccharin (550x sweeter), Aspartame (100x), Sucralose
- Preservatives: Salt, Sugar, Vegetable oils, Sodium benzoate, Propionic acid salts
- Antioxidants: BHT, BHA, SO₂, Na₂SO₃ (prevent oxidation)
- Natural colours: Chlorophyll, Saffron, Caramel, Turmeric
- Synthetic colours: Amaranth, Indigo carmine, Ponceau, Erythrosin
9. Fire Extinguisher
TYPES
- Water: For wood and paper fires
- Soda-acid: Releases CO₂; for oil fires
- Foam: For burning oils (lighter than oil, cuts off O₂)
- Carbon tetrachloride: For electrical fires (non-conductive)
- CO₂: Best extinguisher; heavier than air; blankets fire
10. Chemicals in Cosmetics
COMMON CHEMICALS
| Chemical | Use in Cosmetics |
|---|---|
| Acetone | Nail polish remover |
| Benzaldehyde | Vaseline, shaving cream, perfumes |
| Benzyl alcohol | Cologne, fabric softener |
| Cetyl alcohol | Moisturising creams |
| Ethyl alcohol | Perfumes, hair spray, shampoo |
| Hydroquinone | Moisturising creams |
Summary: Chemistry in Everyday Life at a Glance
| Topic | Key Point |
|---|---|
| Cement | Discovered by Joseph Aspdin (1824); gypsum reduces setting time |
| Pyrex Glass | Borosilicate; heat resistant; lab apparatus |
| Urea | Best fertiliser; 46.6% N; leaves only CO₂ |
| Nylon | First synthetic fibre (1931); stronger than steel |
| Aspirin | Non-narcotic analgesic; anticoagulant |
| Penicillin | Discovered by Fleming (1929) |
| Saccharin | First artificial sweetener; 550x sweeter than sugar |
KEY TAKEAWAYS FOR UPSC
- Cement: Joseph Aspdin (1824); gypsum reduces setting time
- Glass: Annealing prevents brittleness; Pyrex = borosilicate
- Urea: Best fertiliser; 46.6% N; NPK = N + P + K
- Pesticides: DDT (banned), BHC, 2,4-D (herbicide)
- Polymers: Nylon (stronger than steel), Teflon (non-stick), Bakelite (electrical switches)
- Soaps vs Detergents: Detergents work in hard water
- Penicillin: Discovered by Fleming (1929); broad spectrum = Ampicillin, Amoxycillin
- Artificial sweeteners: Saccharin (550x), Aspartame (100x)
- CO₂ fire extinguisher: Best for most fires; heavier than air
- Nobel Prize 2016 Chemistry: Molecular machines (Sauvage, Stoddart, Feringa)
High-Yield Interactive UPSC Quiz (Chemistry — Chemistry in Everyday Life)
Q1. Who discovered Portland cement?
Correct Answer: B. Joseph Aspdin discovered Portland cement in 1824.
Q2. Which glass is used for making laboratory apparatus?
Correct Answer: C. Pyrex glass (borosilicate glass) is heat resistant and used for laboratory apparatus.
Q3. What is the nitrogen content in urea?
Correct Answer: C. Urea contains 46.6% nitrogen, making it the best nitrogenous fertiliser.
Q4. Which polymer is known as the first fully synthetic fibre?
Correct Answer: B. Nylon was the first fully synthetic fibre, developed in 1931.
Q5. Who discovered penicillin?
Correct Answer: B. Alexander Fleming discovered penicillin in 1929.
Q6. Which artificial sweetener is 550 times sweeter than sugar?
Correct Answer: B. Saccharin was the first artificial sweetener and is about 550 times sweeter than cane sugar.
Q7. Which fire extinguisher is best for electrical fires?
Correct Answer: C. Carbon tetrachloride is non-conductive and used for electrical fires.
Q8. What is the process of heating rubber with sulphur called?
Correct Answer: C. Vulcanisation is the process of heating rubber with sulphur to make it hard, strong, and elastic.
Q9. Dettol is a mixture of:
Correct Answer: B. Dettol is a mixture of chloroxylenol and terpineol.
Q10. Which of the following is a biodegradable detergent?
Correct Answer: B. Straight chain hydrocarbons in detergents are biodegradable, while branched chain are non-biodegradable.