ChemistryChemical Kinetics· Class 12
Effect of temperature on rate
“Milk spoils fast on the counter but slowly in the fridge.”
Raising temperature increases reaction rate, roughly doubling it every 10°C.
Memory trick: Hotter → faster.
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.
300 fundamentals
ChemistryOrganic Chemistry — Basic Concepts· Class 11
Catenation of carbon
“From plastics to proteins, everything organic is built on carbon chains.”
Carbon's ability to bond with itself in long chains and rings underlies all organic chemistry.
Memory trick: Carbon links endlessly.
ChemistryOrganic Chemistry — Basic Concepts· Class 11
Functional group
“Swap the functional group and alcohol becomes acid — different smell, different reactions.”
The reactive atom or group that decides an organic molecule's chemistry (–OH, –COOH, etc.).
Memory trick: The group runs the chemistry.
ChemistryOrganic Chemistry — Basic Concepts· Class 11
Isomerism
“Two molecules with identical formulas can be a medicine and a poison.”
Same molecular formula, different arrangement of atoms.
Memory trick: Same formula, different structure.
ChemistryOrganic Chemistry — Basic Concepts· Class 11
Electrophile vs nucleophile
“Chemistry is a dance: electron-rich meets electron-poor.”
Electrophiles are electron-poor (accept electrons); nucleophiles are electron-rich (donate them).
Memory trick: Nucleophile = electron donor.
ChemistryOrganic Chemistry — Basic Concepts· Class 11
Resonance
“Benzene's electrons are smeared into a stable ring, not fixed double bonds.”
Delocalisation of electrons across a molecule, giving extra stability.
Memory trick: Real molecule = hybrid of structures.
ChemistryOrganic Chemistry — Basic Concepts· Class 11
Carbocation stability
“More alkyl 'friends' steady the positive charge.”
Stability order 3° > 2° > 1°, because alkyl groups donate electron density.
Memory trick: More alkyl groups → more stable.
ChemistryHydrocarbons· Class 11
Alkanes, alkenes, alkynes
“Cooking gas (alkane), ripening agent ethene (alkene), welding gas ethyne (alkyne).”
Alkanes have single bonds (saturated); alkenes have C=C; alkynes have C≡C (unsaturated).
Memory trick: -ane single, -ene double, -yne triple.
ChemistryHydrocarbons· Class 11
Saturated vs unsaturated
“Unsaturated fats have C=C 'kinks' that keep oils liquid.”
Saturated hydrocarbons have only single bonds and maximum hydrogens; unsaturated have double/triple bonds.
Memory trick: Double/triple bond = unsaturated.
ChemistryHydrocarbons· Class 11
Markovnikov's rule
“'The rich get richer' — the H-rich carbon gains the H.”
In HX addition to an alkene, H adds to the carbon already having more hydrogens.
Memory trick: H to the H-rich carbon.
ChemistryHydrocarbons· Class 11
Aromaticity of benzene
“Benzene refuses to behave like a normal alkene because breaking its ring costs stability.”
Benzene's planar ring with 6 delocalised electrons is extra stable and prefers substitution to addition.
Memory trick: Aromatic → substitutes, not adds.
ChemistryHydrocarbons· Class 11
Combustion of hydrocarbons
“Every engine and gas stove runs on this reaction.”
Hydrocarbons burn in oxygen to give CO₂ and water, releasing energy.
Memory trick: Fuel + O₂ → CO₂ + H₂O + energy.
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.
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.