Mole fraction
xᵢ = nᵢ / Σ n
One sheet · NCERT · Board revision
Class 12 Chemistry Formula Sheet
31 formulas from Mathematics and Science, chapter by chapter. Search, filter, copy, or print. This is a revision sheet — not a replacement for the textbook derivation.
Practice questions aligned to NCERT topics used in CBSE classrooms. These are original exam-oriented questions for revision — not official CBSE board papers and not a guarantee of any exam question. Always match the textbook issued by your school and the latest PDFs on ncert.nic.in and cbseacademic.nic.in.
🧪 Class 12 · Chemistry
Solutions
Molarity
M = moles of solute / litres of solution
Molality
m = moles of solute / kg of solvent
Raoult (volatile)
p₁ = x₁ p₁°
Relative lowering
(p° − p) / p° = x₂
Elevation of boiling point
ΔT_b = K_b m
Depression of freezing point
ΔT_f = K_f m
Osmotic pressure
π = i C R T
van’t Hoff
i = observed / calculated colligative
🧪 Class 12 · Chemistry
Electrochemistry
Nernst
E = E° − (RT/nF) ln Q ≈ E° − (0.059/n) log Q (25°C)
ΔG°
ΔG° = −n F E°_cell
Conductivity
κ, Λ_m = κ / C (C in mol/cm³ or as in book units)
Kohlrausch
Λ_m° = ν₊ λ₊° + ν₋ λ₋°
Faraday (1st)
w = Z I t, Z = M / (n F)
From chapter list
E=E°−(RT/nF)lnQ
🧪 Class 12 · Chemistry
Chemical Kinetics
Rate law
rate = k [A]ᵐ [B]ⁿ
First order
k = (2.303/t) log ([A]₀ / [A])
Half-life (1st order)
t½ = 0.693 / k
Arrhenius
k = A e^{−Ea/RT}
Two-temperature
log (k₂/k₁) = (Ea/2.303 R) (1/T₁ − 1/T₂)
🧪 Class 12 · Chemistry
The d- and f-Block Elements
Lanthanoid contraction
Steady decrease in size from La to Lu
🧪 Class 12 · Chemistry
Coordination Compounds
Coordination number
Number of ligand donor atoms bound to the metal
Werner primary / secondary
Oxidation number vs coordination number
🧪 Class 12 · Chemistry
Haloalkanes and Haloarenes
SN2
One-step, inversion, preferred by 1°
SN1
Two-step via carbocation, racemisation, preferred by 3°
🧪 Class 12 · Chemistry
Alcohols, Phenols and Ethers
Acidity order (idea)
phenol > water > 1° alcohol (as taught)
Williamson
R−ONa + R′−X → R−O−R′
🧪 Class 12 · Chemistry
Aldehydes, Ketones and Carboxylic Acids
Nucleophilic addition
C=O is the site; HCN, Grignard, etc.
Tollens / Fehling
Aldehydes (not ketones, generally) reduce these reagents
🧪 Class 12 · Chemistry
Amines
Basicity (aqueous idea)
Compare 2°, 1°, 3° as in NCERT discussion
🧪 Class 12 · Chemistry
Biomolecules
Peptide bond
−CO−NH− between amino acids
Also open
FAQs
Are these all official board formulas?
They are the standard NCERT relations used in CBSE Maths and Science papers. Always match the edition issued by your school.
Why are some Biology items short?
Biology is mostly definitions. Only equations and standard ratios (photosynthesis, Hardy–Weinberg, growth models) sit on this sheet.
Will a formula come as-is in the exam?
Often the paper asks you to use a formula, not recite it. Practise a numerical or a derivation after you memorise the line.