EMINENT Admin Team
28 Dec

Combustion & Fuels

Type of HydrocarbonFlame Characteristics
Unsaturated HCYellow flame
Saturated HCClean flame
  • Incomplete burning of petrol and diesel produces Carbon monoxide (CO).

Chemicals & Their Uses

Chemical/CompoundUse
NitrogenFound in natural silk
Blue vitriol (CuSO₄·5H₂O)Fungicide
Zn₃P₂ (Zinc Phosphide)Rodenticide
NaClO₃ (Sodium Chlorate)Herbicide
NitrocelluloseExplosive
TaxolAnti-cancer drug
BOR-A (Boric acid)Antiseptic
CA-FP (Citric acid)Food preservative
AA-P (Acetic acid)Pickle preparation
Milk of Magnesia (Mg(OH)₂)Mild base / Antacid
Lithium bicarbonateTreatment of Rheumatism
AgIArtificial rain
AgBrPreserve photographic images

Food & Biochemistry

  • Invert sugar syrup: Hydrolysis of sucrose → glucose + fructose; sweeter than sucrose, moisture-retaining, less prone to crystallization.
  • Fruits in cold storage last longer due to decreased respiration rate.
  • Blood glucose concentration: mg/dL.
  • Sucralose > Saccharin > Aspartame > Fructose > Sucrose (sweetness ranking)
  • Fructose: sweetest naturally occurring sugar (~2x sucrose)
  • Vinegar: preservative
  • Curcuminoids: Turmeric
  • 1,8-cineole: Cardamom
  • Eugenol: Cloves
  • Piperine: Black pepper
  • Toothpaste: basic, neutralizes acids

Physics & Optics

  • Diffusion of light in atmosphere: due to dust particles.
  • Twinkling of stars: refraction.
  • Red sun at sunrise/sunset: scattering.
  • Looming: optical illusion (ships appear inverted).
  • Optical fiber: denser → rarer → denser, angle > critical angle.
  • TIR examples: diamond shine, soap bubbles, rainbow.
  • Photo cell: fire alarm detection.
  • Ultrasonic waves: fetal growth monitoring, detect metal cracks.
  • Speed of sound: seawater > distilled water.

Light & Radiation

  • Radiation thermometers: pyrometer.
  • Scattering: blue sky, red sunrise/sunset, sea appears blue.
  • Refraction: twinkling stars before sunrise/after sunset.
  • Interference: soap bubbles, kerosene films.
  • Dispersion: rainbow.

Magnetism

TypeMagnetic BehaviorMagnetic Susceptibility (χ)Examples
ParamagneticWeak attraction along fieldSmall, positiveManganese, Aluminium, Chromium, Platinum
FerromagneticStrong attraction along fieldVery large, positive (χ >1000)Iron, Nickel, Cobalt, Gadolinium
DiamagneticWeak repulsion opposite fieldSmall, negative (-1 ≤ χ ≤ 0)Bismuth, Mercury, Copper, Lead, Zinc

Astronomy

  • Sunlight: 8 min 20 sec to Earth.
  • Stars:
    • Dwarf stars: long lifespan (tens-hundreds billion years), slow nuclear reactions.
    • Giant stars: short lifespan (millions-billion years), fast nuclear reactions.
  • Brightest star: Sirius.
  • Cosmic rays: charged particles.

Enzymes & Microbiology

  • Enzymes: biocatalysts, act at site of production.
  • Microbial fuel cells (MFC): convert chemical energy → electricity using bacteria, can treat wastewater.

Materials & Chemistry

MaterialUse/Property
GrapheneCarbon nanostructure, single layer sheet
DiamondTetrahedral, high MP/BP, chemically reacts like graphite
GraphiteHexagonal, high stability
Carbon steelSolid, definite shape/volume
Wrought ironVery pure iron (~99.5%)
PolycarbonateCDs
AcrylicSynthetic wool
BakelitePhenol + formaldehyde condensation
Nylon 6Fabric
TeryleneFabric
TeflonNon-stick plastics
Melamine formaldehyde resinCeramic plastic resin
BUNA-S/NSynthetic rubber
GlyptalFabric
CaSO₄·½H₂OPlaster of Paris
NaHCO₃Baking soda/antacid
Na₂CO₃·10H₂OWashing soda
CuSO₄·5H₂OBlue vitriol
ZnElectroplating cathode process
H₂SO₄Car battery, max in acid rain

Thermodynamics & Heat

  • Latent heat: energy absorbed/released at constant temperature.
  • Conduction: vibration of particles, no bulk movement.
  • Convection: particle movement → currents.
  • Radiation: heat transfer via EM waves.
  • Pressure cooker: raises boiling point → faster cooking.
  • Centrifugation: separates denser/lighter particles.
  • 2nd law: entropy ↑ in isolated system.
  • 3rd law: entropy → constant as temperature → 0K.
  • Thomson effect: temperature variation along conductor → potential variation.
  • Seebeck effect: temperature difference between dissimilar metals → potential difference.

Biology & Medicine

  • Osmosis: water uptake in roots.
  • Photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
  • Respiration in plants: occurs in leaves, stems, roots.
  • Anaerobic respiration: pyruvate → lactic acid + energy → muscle cramps.
  • Tulsi: phenols & flavonoids.
  • PFAS: bioaccumulative, persistent in environment, present in food/water.
  • Hydrogels: controlled drug delivery, mobile AC, industrial lubricants.
  • Mitochondrial replacement therapy: prevents mitochondrial diseases.
  • Nitric oxide (NO): vasodilation, increased blood flow.

Human Anatomy & Physiology

TermDetail
BlindspotOptic nerve connects to retina
PerspirationWater, minerals, lactate, urea
Blood glucosemg/dL
Contact lensesHydrogel
TeethToothpaste basic, neutralizes acid

Sound & Noise

Noise LevelExample
0–30 dBPractically inaudible
31–45 dBSilent sounds
46–65 dBStandard conversation
66–90 dBElectric beard trimmers
91–100 dBCars without mufflers
101–125 dBAircraft takeoff
>125 dBRocket launch
  • Timbre: distinguishes sounds of same pitch/loudness.

Metals & Alloys

AlloyComposition
BrassZn + Cu
BronzeCu + Sn
Stainless steelC:0.03, Mn:2, Si:0.75, Cr:16–18, Ni:10–14, Mo:2–3, P:0.045, S:0.03, N:0.1
Wrought ironPure iron (~99.5%)
  • Noble metals: Au, Ag, Pt
  • Platinum group: Pt, Os, Ir, Ru, Rh, Pd

Acids, Bases & Salts

SubstancepH/Use
Milk of MagnesiapH 10.5
NaHCO₃Baking soda, antacid
Na₂CO₃Washing soda
HCl gas (dry)No litmus color change
Oxalic acidLeather bleaching
Acetic acidFood processing
Citric acidWashing metals
Benzoic acidBatteries
VinegarPreservative
PFASPersistent chemical

Light & Color

  • Chlorophyll absorbs red & blue light.
  • Sr²⁺ → red color in fireworks, Ca²⁺ → orange, Cu²⁺ → blue.
  • Blue light scatters more → sky appears blue.

Gases & Atmosphere

  • Greenhouse gases: CO₂ (72%), CH₄ (18%), NOx (7%)
  • Laughing gas: N₂O
  • Ethylene: artificial ripening of fruits
  • Dry ice: solid CO₂
  • Radon: radioactive, absent in atmosphere
  • CO₂ + ethanol → 2CH₃CH₂ONa + H₂

Chemical Laws

LawStatement
Law of Definite ProportionsCompound always has same element ratio
Law of Multiple ProportionsMass ratio of elements in compounds = small integers
Avogadro’s LawEqual volumes of gas → equal molecules
Conservation of MassMass of reactants = mass of products
CharlesV ∝ T at constant P
BoyleP ∝ 1/V
GrahamRate of diffusion ∝ 1/√Molecular weight

Electrochemistry & Cells

  • Electroplating: utensil = cathode, pure metal = anode.
  • Battery: Anode negative during discharge, positive during charge.
  • Diodes: Anode = positive.
  • Electrolytic cells: Anode positive.

Radioactivity & Isotopes

ElementUse
CoCaCobalt isotope, cancer treatment
ReSeCaRadium isotope, secondary cancer treatment
Isotopessame chemical properties (same atomic number)
  • Radon: radioactive, absent in air.

Organic Chemistry

  • Ethanol: C₂H₆O, volatile, flammable, universal solvent.
  • PFAS: persistent environmental chemicals.
  • Nitrocellulose: explosive.
  • Ethylene: fruit ripening.
  • Nitroglycerine: explosive, synthesized by Ascanio Sobrero (1846).
  • Fructose: sweetest sugar.
  • Saccharin, Aspartame, Sucralose, Alitame: artificial sweeteners.
  • Soaps: hydrophilic head, hydrophobic tail.

Metallurgy

  • Smelting: metal obtained in fused state.
  • Calcination: heating solids to remove volatiles.
  • Reduction: metal oxide + carbon → pure metal.
  • Ores roasted to remove sulfur.

Miscellaneous

  • Galileo: first to measure speed.
  • Lead: poorest conductor.
  • Bromine: red liquid.
  • Welding gases: O₂ + acetylene.
  • Visible light: 3900–7600 Å.
  • Detergents: sulfonates.
  • MFC: converts chemical energy → electricity using bacteria.
  • PFAS: persistent, bioaccumulative.
  • Fermentation: sugar → alcohol + CO₂.
  • Hydrofluoric acid: not stored in glass.
  • Nylon, Terylene: fabrics
  • Kevlar → Fluorene → Graphene → Black Gold

Periodic Table & Elements

Atomic NoElement
98Californium (Cf)
99Einsteinium (Es)
100Fermium (Fm)
101Mendelevium (Md)
102Nobelium (No)
103Lawrencium (Lr)
104Rutherfordium (Rf)
105Dubnium (Db)
106Seaborgium (Sg)
107Bohrium (Bh)
108Hassium (Hs)
109Meitnerium (Mt)
110Darmstadtium (Ds)
111Roentgenium (Rg)
112Copernicium (Cn)
113Nihonium (Nh)
114Flerovium (Fl)
115Moscovium (Mc)
116Livermorium (Lv)
117Tennessine (Ts)
118Oganesson (Og)
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