Chemistry — Last-Minute Revision
High-priority revision for the TS Inter 2nd Year Chemistry board exam — named reactions, key formulae, inorganic processes and exam strategy. Paper: 60 marks · 3 hours.
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High-Yield Chapters
- •p-Block Elements — oxoacids of S, N, P; XeF₂, XeF₄ structures (high frequency LAQ)
- •Organic Compounds (CHO) — nucleophilic addition, aldehyde reactions (LAQ)
- •Electrochemistry — Nernst equation, electrolysis, conductance (LAQ+SAQ)
- •Haloalkanes — SN1 vs SN2, halogenation mechanisms (SAQ+LAQ)
- •d and f Block / Coordination Compounds — IUPAC, isomers, CFT (SAQ+LAQ)
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Named Reactions to Recall
- •Sandmeyer reaction — diazonium salt + CuCl/CuBr → haloarene
- •Cannizzaro reaction — formaldehyde self-oxidation/reduction (no α-H)
- •Aldol condensation — aldehyde + NaOH (with α-H)
- •Hell-Volhard-Zelinsky — carboxylic acid + Br₂/P
- •Williamson synthesis — alkoxide + alkyl halide → ether
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Key Formulae
- •Nernst equation: E = E° − (RT/nF) ln Q = E° − (0.0592/n) log Q at 25°C
- •ΔTb = Kb × m (boiling point elevation)
- •ΔTf = Kf × m (freezing point depression)
- •Osmotic pressure: π = CRT = (n/V)RT
- •van't Hoff factor: i = observed moles / normal moles
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Inorganic Quick-Recall
- •SO₃ → H₂SO₄ via oleum (contact process)
- •NH₃ → NO → NO₂ → HNO₃ (Ostwald process)
- •Moist air + S → SO₂ → SO₃: catalytic oxidation uses V₂O₅
- •Fe₂O₃ + CO → Fe + CO₂ (blast furnace, reduction)
- •MnO₄⁻ colour — KMnO₄ is purple (Mn is +7 oxidation state)
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Exam-Day Tips
- •For organic reactions, draw the mechanism arrows — marks given for electron movement
- •Write IUPAC names carefully — wrong name = zero marks for that question
- •For p-Block structures, draw Lewis dot structures with bond angles
- •In electrochemistry numericals, state the half-reactions before calculating EMF
- •For colligative properties, convert concentration to molality before applying formula