ChemistryAlcohols, Phenols & Ethers· Class 12
Alcohols
“Ethanol — in fuels, sanitisers and drinks — is the most famous alcohol.”
Contain –OH; they can be oxidised to aldehydes/ketones and are good solvents.
Memory trick: –OH group.
Fundamentals
1,200 must-knows for NEET & JEE
The core facts every aspirant should own — each a titled nugget with a real-world story, the concept in plain words, and a memory trick. Works even when the internet doesn't.
1,200 fundamentals
ChemistryAldehydes, Ketones & Carboxylic Acids· Class 12
Aldehydes vs ketones
“Aldehydes are easily oxidised further; ketones resist — a classic distinguishing test.”
Both have C=O; an aldehyde has it at the chain end (–CHO), a ketone in the middle (C–CO–C).
Memory trick: Aldehyde: end; ketone: middle.
ChemistryAldehydes, Ketones & Carboxylic Acids· Class 12
Carboxylic acids
“Vinegar, citrus and even ant stings owe their sourness to carboxylic acids.”
Contain –COOH and are weak acids that release H⁺.
Memory trick: –COOH → sour, weakly acidic.
ChemistryAldehydes, Ketones & Carboxylic Acids· Class 12
Esterification
“The fruity smells of pineapple and banana are esters.”
An acid plus an alcohol gives a sweet-smelling ester and water.
Memory trick: Acid + alcohol → ester + water.
ChemistryAmines· Class 12
Amines
“Fishy smells come from amines; many drugs are amines too.”
Organic derivatives of ammonia containing nitrogen; they are basic.
Memory trick: N-containing → basic.
ChemistryBiomolecules· Class 12
Carbohydrates
“Rice and bread are starch — chains of glucose your body unpacks for energy.”
Polyhydroxy aldehydes/ketones; the body's quick energy source (glucose, starch, cellulose).
Memory trick: Sugars & their polymers.
ChemistryBiomolecules· Class 12
Proteins
“Enzymes, muscles and antibodies are all proteins.”
Polymers of amino acids linked by peptide bonds; they build and run the body.
Memory trick: Amino-acid chains.
ChemistryBiomolecules· Class 12
Denaturation
“A frying egg turns solid and white as its proteins denature.”
Heat or pH can unfold a protein, destroying its shape and function.
Memory trick: Lose shape → lose function.
ChemistryBiomolecules· Class 12
Vitamins
“Scurvy — the sailor's disease — is simply a lack of vitamin C.”
Micronutrients the body needs in tiny amounts; fat-soluble (A, D, E, K) or water-soluble (B, C).
Memory trick: A,D,E,K store in fat; B,C wash out.
ChemistryPolymers· Class 12
Addition vs condensation polymers
“Plastic bags are addition polymers; nylon ropes are condensation polymers.”
Addition polymers form by adding monomers (polythene); condensation polymers form by losing small molecules like water (nylon).
Memory trick: Condensation loses a small molecule.
ChemistryThe p-Block Elements· Class 11
Allotropes of carbon
“The hardest natural material and pencil 'lead' are the same element, arranged differently.”
Diamond (hard, insulating) and graphite (soft, conducting) are both pure carbon.
Memory trick: Same atom, different structure.
ChemistryPeriodic Table & Periodicity· Class 11
Diagonal relationship
“Lithium behaves oddly like magnesium, not like its own group.”
Some period-2 elements resemble the period-3 element diagonally below-right (Li–Mg, Be–Al).
Memory trick: Diagonal neighbours can be alike.
ChemistryThe d- and f-Block Elements· Class 12
Transition metals: variable valency
“Iron can be Fe²⁺ or Fe³⁺ — which is why blood and rust differ in colour.”
d-block metals show multiple oxidation states and form coloured compounds.
Memory trick: d-electrons → many states, colours.
ChemistryCoordination Compounds· Class 12
Coordination compound
“Haemoglobin is an iron coordination complex that ferries your oxygen.”
A central metal ion bonded to surrounding ligands that donate electron pairs.
Memory trick: Metal + ligands.
ChemistryChemical Kinetics· Class 12
Catalysis in industry
“The fertiliser feeding half the world is made possible by a metal catalyst.”
Catalysts make huge industrial processes economical (iron in the Haber process for ammonia).
Memory trick: Catalysts power industry.
ChemistryEnvironmental Chemistry· Class 11
Greenhouse effect
“Too much CO₂ turns Earth's natural blanket into an electric one.”
Gases like CO₂ trap outgoing heat, warming the planet.
Memory trick: CO₂ traps heat.
ChemistryEnvironmental Chemistry· Class 11
Ozone layer
“The ozone 'sunscreen' high above us blocks rays that would otherwise scorch DNA.”
Stratospheric ozone (O₃) shields life from harmful UV radiation.
Memory trick: Ozone = Earth's UV shield.
ChemistryStructure of Atom· Class 11
Bohr's model of hydrogen
“Neon signs glow in set colours because electrons jump fixed rungs.”
Electrons orbit in fixed energy levels; light is emitted or absorbed only in jumps between them.
Memory trick: Energy comes in quantised jumps.
ChemistryStructure of Atom· Class 11
Heisenberg uncertainty principle
“At the quantum scale, looking closer blurs the picture.”
You cannot know an electron's exact position and momentum simultaneously.
Memory trick: Position and momentum trade off.
ChemistryStructure of Atom· Class 11
Shapes of orbitals
“Orbitals are probability clouds, not tracks.”
s orbitals are spherical, p orbitals dumbbell-shaped, d orbitals cloverleaf.
Memory trick: s sphere, p dumbbell.
ChemistryStructure of Atom· Class 11
Anomalous electronic configurations
“Nature bends its own filling rules to reach a more stable arrangement.”
Chromium is 3d⁵ 4s¹ and copper 3d¹⁰ 4s¹ because half- and fully-filled d subshells are extra stable.
Memory trick: Half/fully-filled d = stable.
ChemistryStructure of Atom· Class 11
Electromagnetic spectrum
“The same physics carries your Wi-Fi, warms you as infrared and tans you as UV.”
Light ranges from radio waves to gamma rays; visible light is a thin slice.
Memory trick: Higher frequency = more energy.
ChemistryThe s-Block Elements· Class 11
Alkali metals
“Drop sodium in water and it fizzes, melts and can ignite.”
Group-1 metals are soft, highly reactive and stored under oil.
Memory trick: Reactivity rises down the group.
ChemistryThe s-Block Elements· Class 11
Flame colours
“Fireworks paint the sky using metal-salt flame colours.”
Alkali and alkaline-earth metals give characteristic flame colours (Na yellow, K lilac, Ca brick-red).
Memory trick: Na = yellow, K = lilac.