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IIT JAM MA study materials
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IIT JAM MA: IIT JAM Chemistry: Physical, Organic and Inorganic Reasoning

IIT JAM MA · Work through your exam, one topic at a time.

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IIT JAM Chemistry: Physical, Organic and Inorganic Reasoning

IIT JAM CY spans physical, organic and inorganic chemistry. Numerical physical chemistry, reaction mechanisms, stereochemistry, periodicity and coordination chemistry are central; answers must connect structure to properties and equations to units.

Core rules and concepts

  • Thermodynamics: ΔG = ΔH − TΔS; at equilibrium ΔG = 0; ΔG° = −RT ln K. Enthalpy and entropy are state functions.
  • Kinetics: rate = k[A]^m[B]^n; first-order half-life t½ = ln2/k is independent of initial concentration; Arrhenius k = A e^(−Ea/RT).
  • Organic mechanisms: SN1 proceeds through carbocation intermediates and favors polar protic solvents; SN2 is concerted and sensitive to steric hindrance. E1 and E2 compete with substitution.
  • Stereochemistry: assign R/S by CIP priority; a molecule with n stereocenters has up to 2ⁿ stereoisomers, reduced by meso forms.
  • Aromaticity: cyclic, planar, fully conjugated, with 4n + 2 π electrons.
  • Inorganic: periodic trends, VSEPR geometry, crystal-field splitting and CFSE; coordination number determines common geometry.
  • Spectroscopy: IR identifies functional groups; ¹H NMR uses chemical shift, integration and splitting.

Worked example

A first-order reaction has t½ = 20 min. What time is needed for 75% decomposition? After one half-life, 50% remains; after two half-lives, 25% remains, which means 75% has decomposed. Therefore t = 2 × 20 = 40 min. Equivalently, k = ln2/20 and t = ln(4)/k = 40 min.

Traps that cost marks

Read “75% decomposed” versus “75% remaining” carefully. Use kelvin in gas-law and thermodynamic expressions. Do not assume every molecule with stereocenters has 2ⁿ isolable isomers; meso compounds reduce the count. Check formal charge and lone pairs before predicting geometry.

Key points

  • First-order half-life is independent of concentration.
  • ΔG° = −RT ln K links thermodynamics and equilibrium.
  • SN1 favors carbocations; SN2 is backside attack.
  • Aromatic systems need 4n + 2 π electrons.
  • Meso compounds reduce the 2ⁿ stereoisomer count.