Chemistry — Formula Sheet
Key formulas and reaction patterns for TS Intermediate 2nd Year Chemistry — 13 chapters as per TGBIE Annual Plan 2025-26. High-weightage chapters shown with fuller formula sets. Paper: 60 marks · 3 hours.
1.
Solid State
- Simple cubic: a = 2r; BCC: a = 4r/√3; FCC: a = 2√2 r
- Density of unit cell: d = Z·M / (N_A·a³)
- Packing efficiency — SC: 52.4%; BCC: 68%; FCC/CCP: 74%
- Number of atoms per unit cell — SC: 1; BCC: 2; FCC: 4
2.
Solutions
- Molality: m = moles of solute / kg of solvent
- Raoult's law: P_A = x_A · P°_A; P_total = x_A·P°_A + x_B·P°_B
- Relative lowering of vapour pressure: (P°−P)/P° = x_B
- Elevation in boiling point: ΔT_b = K_b · m
- Depression in freezing point: ΔT_f = K_f · m
- Osmotic pressure: π = iCRT = inRT/V
- van't Hoff factor: i = ΔT_obs / ΔT_calc
3.
Electrochemistry & Chemical Kinetics
- Nernst equation: E_cell = E°_cell − (RT/nF) ln Q = E°_cell − (0.0591/n) log Q at 25°C
- ΔG° = −nFE°_cell = −RT ln K
- Conductance (G) = 1/R; Molar conductance: Λ_m = κ/C
- Kohlrausch's law: Λ°_m = Σ λ°_cations + Σ λ°_anions
- Rate law: rate = k[A]^m[B]^n
- First-order: t₁/₂ = 0.693/k; k = (2.303/t) log(a/(a−x))
- Arrhenius equation: k = Ae^(−Ea/RT); log(k₂/k₁) = Ea/2.303R · (1/T₁ − 1/T₂)
7.
d and f Block & Coordination Compounds
- Magnetic moment: μ = √(n(n+2)) BM (n = unpaired electrons)
- CFSE in octahedral: −0.4Δ_o per t₂g electron, +0.6Δ_o per e_g electron
- Werner's theory: CAN = primary valency + secondary (coordination) valency
- IUPAC: ligands named before metal; anionic complex ends -ate
- Effective atomic number (EAN) = Z − oxidation state + 2 × CN
8.
Polymers
- Degree of polymerisation (DP) = M_polymer / M_monomer
- Free radical initiation: I → 2R·; Propagation: R· + M → RM·
- Step-growth (condensation): conversion p; DP = 1/(1−p) (Carothers equation)
11.
Haloalkanes & Haloarenes
- SN2: rate = k[RX][Nu⁻]; inversion of configuration; primary RX favoured
- SN1: rate = k[RX]; retention/racemisation; tertiary RX favoured; carbocation intermediate
- Reactivity order (halides): RI > RBr > RCl > RF
- Sandmeyer: ArN₂⁺ + CuCl → ArCl; CuBr → ArBr; CuCN → ArCN
- HVZ reaction: α-halogenation of carboxylic acids with X₂/P
12.
Organic Compounds (C, H and O)
- Alcohols — Lucas test: 3° > 2° > 1° reactivity
- Aldehydes — Tollens: RCHO + 2[Ag(NH₃)₂]⁺ → RCO₂⁻ + 2Ag (silver mirror)
- Aldehydes — Fehling: RCHO + 2Cu²⁺ → RCO₂⁻ + Cu₂O (brick-red ppt)
- Cannizzaro: 2HCHO → CH₃OH + HCOO⁻ (no α-H, conc. NaOH)
- Aldol condensation: CH₃CHO → aldol → crotonaldehyde (−H₂O)
- Williamson synthesis: RONa + R′X → R−O−R′ (ether)
13.
Organic Compounds Containing Nitrogen
- Basicity order: aliphatic amines > NH₃ > aromatic amines
- Hinsberg test: 1° amines → soluble sulfonamide; 2° → insoluble; 3° → no reaction
- Diazonium coupling: ArN₂⁺ + Ar′OH → Ar−N=N−Ar′ (azo dye, alkaline medium)
- Gabriel synthesis: phthalimide + RX → 1° amine
- Hoffman bromamide reaction: RCONH₂ + Br₂ + NaOH → RNH₂