CBSE Class 12 Chemistry (2026) has 10 chapters splitting into three scoring zones: Physical Chemistry (Ch 1–3, 23 marks — where all the numerical formulas live), Inorganic (Ch 4–5, 14 marks), and Organic (Ch 6–9, 33 marks — where ~25 name reactions decide the conversions). This page compiles both: every physical-chemistry formula chapter-wise, plus the complete organic name-reactions map.
Where the 70 marks live
| Chapter | Marks |
|---|---|
| Solutions | 7 |
| Electrochemistry | 9 — highest single chapter |
| Chemical Kinetics | 7 |
| d- and f-Block Elements | 7 |
| Coordination Compounds | 7 |
| Haloalkanes & Haloarenes | 6 |
| Alcohols, Phenols & Ethers | 6 |
| Aldehydes, Ketones & Carboxylic Acids | 8 — organic's heavyweight |
| Amines | 6 |
| Biomolecules | 7 |
Physical 23 + Inorganic 14 + Organic 33 = 70 theory marks (+30 practical). The old chapters — Solid State, Surface Chemistry, p-Block, Polymers, Everyday Life — are not in the current rationalized syllabus.
Ch 1 — Solutions 7 marks
| Formula | Used for |
|---|---|
| M = moles of solute / V(L); m = moles / kg solvent | Molarity (changes with T) vs molality (doesn't) |
| x₁ = n₁/(n₁ + n₂) | Mole fraction; x₁ + x₂ = 1 |
| p = K_H · x | Henry's law — gas solubility numericals |
| p = p° x (solvent) | Raoult's law; basis of all colligative properties |
| (p° − p)/p° = x₂ | Relative lowering of vapour pressure |
| ΔT_b = K_b · m; ΔT_f = K_f · m | Boiling-point elevation, freezing-point depression |
| π = CRT | Osmotic pressure — best for finding molar mass of polymers/proteins |
| i = observed property / calculated property | van't Hoff factor; i > 1 dissociation, i < 1 association — multiply i into every colligative formula for electrolytes |
Ch 2 — Electrochemistry 9 marks
| Formula | Used for |
|---|---|
| E°(cell) = E°(cathode) − E°(anode) | Standard cell potential from half-cells |
| E = E° − (0.059/n) log Q (at 298 K) | Nernst equation — the chapter's guaranteed numerical |
| ΔG° = −nFE° | Link between cell potential and spontaneity |
| ΔG° = −2.303 RT log K_c | Equilibrium constant from E° |
| Λ_m = κ × 1000 / M | Molar conductivity from conductivity κ |
| Λ°_m = ν₊λ°₊ + ν₋λ°₋ | Kohlrausch's law — Λ° of weak electrolytes |
| α = Λ_m / Λ°_m | Degree of dissociation of a weak electrolyte |
| m = Z I t; Q = n F | Faraday's laws — electrolysis deposition numericals |
Ch 3 — Chemical Kinetics 7 marks
| Formula | Used for |
|---|---|
| Zero order: [A] = [A]₀ − kt; t½ = [A]₀/2k | Straight-line [A] vs t; half-life depends on [A]₀ |
| First order: k = (2.303/t) log([A]₀/[A]) | THE kinetics numerical — appears virtually every year |
| First order: t½ = 0.693/k | Half-life independent of concentration — classic MCQ |
| k = A e^(−Ea/RT) | Arrhenius equation — temperature dependence |
| log(k₂/k₁) = (Ea/2.303R)(1/T₁ − 1/T₂) | Two-temperature form — the Ea-finding 3-marker |
Ch 4–5 — Inorganic: the few formulas that exist 14 marks
Inorganic chemistry is concept-and-exception territory, but two calculable items repeat in papers:
| Formula / rule | Used for |
|---|---|
| μ = √(n(n + 2)) BM | Magnetic moment from n unpaired electrons — d-block's only real numerical |
| E°(M³⁺/M²⁺) trends; lanthanoid contraction | Reasoning questions on d/f-block properties |
| Coordination number, oxidation state, IUPAC naming rules | Coordination compounds — naming and isomerism are procedure, not formula |
| Hybridisation → geometry (d²sp³ octahedral, dsp² square planar, sp³ tetrahedral) | Valence bond treatment of complexes |
Ch 6–9 — The organic name reactions map 33 marks
Organic chemistry's "formulas" are its name reactions — CBSE asks them directly ("write the reaction"), in conversions, and in mechanism questions. Here is the full map, chapter by chapter:
Haloalkanes & Haloarenes (6 marks)
| Name reaction | What it converts |
|---|---|
| Sandmeyer reaction | ArN₂⁺Cl⁻ → Ar–Cl / Ar–Br / Ar–CN (with Cu₂X₂) |
| Finkelstein reaction | R–Cl/Br + NaI (dry acetone) → R–I |
| Swarts reaction | R–Cl + AgF/Hg₂F₂ → R–F |
| Wurtz reaction | 2 R–X + 2Na (dry ether) → R–R |
| Fittig / Wurtz–Fittig | Ar–X couplings: Ar–Ar / Ar–R |
Alcohols, Phenols & Ethers (6 marks)
| Name reaction | What it converts |
|---|---|
| Williamson ether synthesis | R–X + R′ONa → R–O–R′ (best with 1° halide) |
| Kolbe's reaction | Phenol → salicylic acid (NaOH, CO₂, then H⁺) |
| Reimer–Tiemann reaction | Phenol → salicylaldehyde (CHCl₃/NaOH) |
| Esterification | R–OH + R′COOH ⇌ ester (conc. H₂SO₄) |
Aldehydes, Ketones & Carboxylic Acids (8 marks)
| Name reaction | What it converts |
|---|---|
| Rosenmund reduction | Acyl chloride → aldehyde (H₂, Pd–BaSO₄) |
| Stephen reaction | Nitrile → aldehyde (SnCl₂/HCl, then H₃O⁺) |
| Etard reaction | Toluene → benzaldehyde (CrO₂Cl₂) |
| Gattermann–Koch reaction | Benzene → benzaldehyde (CO, HCl, AlCl₃) |
| Clemmensen reduction | C=O → CH₂ (Zn–Hg / conc. HCl) |
| Wolff–Kishner reduction | C=O → CH₂ (NH₂NH₂, KOH/glycol) |
| Aldol condensation | 2 aldehydes/ketones with α-H → β-hydroxy → enal (dil. NaOH) |
| Cannizzaro reaction | 2 HCHO/ArCHO (no α-H) + conc. NaOH → alcohol + acid salt |
| HVZ reaction (Hell–Volhard–Zelinsky) | R–COOH → α-halo acid (X₂ / red P) |
| Tollens' / Fehling's tests | Distinguish aldehydes (silver mirror / red Cu₂O) from ketones |
Amines (6 marks)
| Name reaction | What it converts |
|---|---|
| Hofmann bromamide degradation | Amide → 1° amine with ONE CARBON LESS (Br₂/NaOH) |
| Gabriel phthalimide synthesis | Pure 1° aliphatic amines (fails for aromatic) |
| Carbylamine reaction | 1° amine + CHCl₃/KOH → foul isocyanide — the 1° amine test |
| Diazotisation | Ar–NH₂ + NaNO₂/HCl (0–5°C) → ArN₂⁺Cl⁻ |
| Coupling reaction | ArN₂⁺ + phenol/aniline → azo dye (orange/yellow) |
| Hinsberg test | Distinguish 1°/2°/3° amines with benzenesulphonyl chloride |
Biomolecules (7 marks) is descriptive — glucose reactions, protein structure, vitamins, DNA/RNA differences — no formula set, revise from notes.
Memory tricks for the reactions map
Group by carbon count. The examiner's favourite conversion trap is chain length: Hofmann bromamide gives an amine with one carbon less; the nitrile/cyanide route (R–X → R–CN → hydrolyse or reduce) adds one carbon more. When a conversion changes chain length, one of these two is almost certainly the intended path.
Learn reagents as fingerprints, not lists. CrO₂Cl₂ = Etard. Zn–Hg/HCl = Clemmensen. NH₂NH₂/KOH = Wolff–Kishner. SnCl₂/HCl = Stephen. Br₂/NaOH = Hofmann. Seeing the reagent should trigger the reaction name instantly — that's exactly how MCQs and assertion-reason questions test it.
The phenol pair: Kolbe gives the acid (salicylic acid — K and acid both "hard" sounds), Reimer–Tiemann gives the aldehyde (salicylaldehyde). Students swap these two every year; anchor them once.
α-H decides aldol vs Cannizzaro: α-hydrogen present → aldol; absent (HCHO, benzaldehyde) → Cannizzaro. One structural check answers every "predict the product with NaOH" question.
The complete handwritten Chemistry formula sheet — formulas + reactions, one set
This page is the map; the sheet is the full territory:
- Full 2026-27 syllabus — physical formulas, inorganic trends and every organic name reaction with structures
- Colour-coded reaction boxes and mechanisms drawn out — not just names
- Real handwritten notes by toppers — IITians, NITians and NEET rankers
- Instant PDF or printed book (COD available, all-India delivery)
- Available in English and Hindi medium
FAQs
How many formulas are there in Class 12 Chemistry?
About 30–35 numerical formulas concentrated in Physical Chemistry (Solutions, Electrochemistry, Kinetics), plus roughly 25 organic name reactions that function as the "formulas" of Chapters 6–9.
Which chapter has the highest weightage in Class 12 Chemistry 2026?
Electrochemistry at 9 marks is the highest single chapter, and Aldehydes, Ketones & Carboxylic Acids at 8 marks leads organic. As blocks, Organic (33) > Physical (23) > Inorganic (14).
Which name reactions are most important for boards?
The most repeated set: Sandmeyer, Williamson, Kolbe, Reimer–Tiemann, Rosenmund, Stephen, Etard, Clemmensen, Wolff–Kishner, aldol, Cannizzaro, HVZ, Hofmann bromamide, Gabriel, carbylamine and the coupling reaction.
Is Solid State or Surface Chemistry in the 2026 syllabus?
No. Solid State, Surface Chemistry, p-Block, Polymers and Chemistry in Everyday Life are all removed under the rationalized syllabus — the paper comes from the current 10 chapters only.
How do I remember organic name reactions easily?
Learn reagents as fingerprints (CrO₂Cl₂ → Etard, Zn–Hg/HCl → Clemmensen), group reactions by carbon-count change, and practise conversions backwards from product to reaction.
What is the difference between Kolbe's and Reimer–Tiemann reactions?
Both start from phenol: Kolbe's (CO₂/NaOH) gives salicylic acid, while Reimer–Tiemann (CHCl₃/NaOH) gives salicylaldehyde.
Is there a Class 12 Chemistry formula sheet in Hindi?
Yes — the handwritten formula sheet linked above is available in both English and Hindi medium versions, with the same reactions and structures.
Are numericals asked from Physical Chemistry every year?
Effectively yes — first-order kinetics, the Nernst equation, colligative properties with the van't Hoff factor, and Faraday's laws are near-annual fixtures worth targeted practice.