Mocktestgen
⚗️

JEE Advanced · Cheatsheet

Chemistry Quick Revision

Multi-step synthesis, exception-heavy inorganic, high-yield physical.

Physical — kinetics & equilibrium tricks

  • Pseudo 1st order: excess of one reactant (hydrolysis of ester).
  • Steady state approximation for intermediates.
  • Ostwald dilution law for weak electrolytes: Ka = Cα²/(1−α).
  • Activity coeff for non-ideal solutions.
  • Le Chatelier + Van't Hoff (d ln K/dT = ΔH°/RT²).

Electrochemistry — advanced

  • Concentration cell: E = (0.0591/n) log([conc high]/[conc low]).
  • Fuel cell (H₂–O₂) η ~70% vs Carnot.
  • Corrosion: anodic Fe → Fe²⁺; cathodic O₂+H₂O+4e⁻ → 4OH⁻.
  • Overpotential in electrolysis.

Inorganic — salt analysis

  • Cation Group I: dil HCl → Ag⁺, Pb²⁺, Hg₂²⁺ (white).
  • II: H₂S/HCl → Cu²⁺ (black), Cd²⁺ (yellow), Bi³⁺, As³⁺.
  • IIIA: NH₄Cl+NH₄OH → Fe(OH)₃ (brown), Al(OH)₃ (white gel).
  • IV: H₂S/NH₄OH → Zn (white), Ni (black), Co (black), Mn (buff).
  • V: (NH₄)₂CO₃ → Ba, Sr, Ca (white).
  • VI: Mg → white on adding Na₂HPO₄.
  • Flame: Na (yellow), K (violet), Ca (brick), Sr (crimson), Ba (apple green), Cu (green).
  • Anion: CO₃²⁻ (effervescence), SO₄²⁻ (BaCl₂ ppt), Cl⁻ (AgCl white, soluble in NH₃), Br⁻ (pale yellow), I⁻ (yellow), NO₃⁻ (brown ring).

Coordination — advanced

  • Isomerism: geometrical, optical, linkage, ionization, coordination, hydrate.
  • Chelate effect: entropy-driven stability boost.
  • μ = √(n(n+2)) BM (spin only).
  • [Fe(CN)₆]⁴⁻ low spin diamagnetic; [Fe(H₂O)₆]²⁺ high spin.
  • sp³d² inner (d²sp³) vs outer (sp³d²) orbital complexes.
  • Applications: chlorophyll (Mg²⁺), haemoglobin (Fe²⁺), vitamin B12 (Co³⁺).

Organic — retrosynthesis & multi-step

  • Disconnect at C=O, C–X, C–OH; look for α,β-unsaturated to Michael or aldol.
  • Protect –OH (as TBDMS or acetal) before Grignard.
  • Convert to synthon: RMgBr, R–X, R–CO⁺.
  • Common tricks: HVZ (α-halogenation of acid), Reformatsky (Zn+α-haloester).
  • Pericyclic: Diels–Alder [4+2]; Woodward–Hoffmann.
  • Rearrangements: Pinacol–pinacolone, Beckmann (oxime → amide), Hofmann (amide → 1° amine, C↓1).

Organic — spectroscopy quick

  • IR: O–H broad 3200–3550, N–H 3300–3500, C=O 1700, C≡N 2200.
  • ¹H NMR: TMS δ=0. Aromatic 6–9, vinyl 5–7, α to C=O 2–3, OH exchangeable.
  • Multiplicity: n+1 rule.
  • Mass spec: M⁺ molecular ion; McLafferty rearrangement in ketones.

Test what you just revised

Take a free JEE Advanced Chemistry mock and lock it in.

Start a mock test

More JEE Advanced cheatsheets

Other exams