62+ formula cards with KaTeX-rendered equations, units, traps, deterministic tools, and metadata-only NCERT locator context. Free, no login needed.
The launch formula layer connects every high-risk expression to its chapter, outcome, constants, common trap, deterministic tool, and answer-masked practice path. Official sources remain locator metadata; this page does not copy textbook passages.
CBSE-12-CHEM-CH1
Molarity, molality, mole fraction
Constants and units
Common trap
Do not use solution mass where solvent mass is required for molality.
CBSE-12-CHEM-CH1
Raoult law, partial pressure, and vapor composition
Constants and units
Common trap
Do not use mass fraction where mole fraction is required.
CBSE-12-CHEM-CH1
Ebullioscopy, molality, and molar mass
Constants and units
Common trap
Do not use solution mass instead of solvent mass.
CBSE-12-CHEM-CH2
Nernst equation and reaction quotient
Constants and units
Common trap
A flipped reaction quotient reverses the sign of the correction.
CBSE-12-CHEM-CH2
Limiting molar conductivity and weak electrolyte dissociation
Constants and units
Common trap
Do not use measured Lambda_m as Lambda_m0 for weak electrolytes.
CBSE-12-CHEM-CH2
Faraday laws, charge, and deposited mass
Constants and units
Common trap
Do not forget to divide by electron count n for multivalent ions.
CBSE-12-CHEM-CH3
Integrated first-order rate law
Constants and units
Common trap
First-order half-life is independent of starting concentration.
CBSE-12-CHEM-CH4
d-electron count and unpaired electrons
Constants and units
Common trap
Count d electrons after removing ns electrons first for transition-metal cations.
CBSE-12-CHEM-CH5
Octahedral/tetrahedral splitting and spin state
Constants and units
Common trap
Do not apply octahedral orbital order directly to tetrahedral complexes.
Showing 62 of 62 formulas
where: n = moles, m = mass (g), M = molar mass (g/mol), N = number of particles, N_A = 6.022\times 10^{23}
where: Concentration in mol/L. Temperature-dependent (volume changes).
where: Concentration in mol/kg. Temperature-independent.
where: Dimensionless ratio of moles of A to total moles.
where: Mass-based elemental composition of a compound.
where: Molecular formula = (empirical formula)_n.
where: n = principal quantum number, Z = atomic number.
where: Energy of the n-th orbit. Negative ⇒ bound state.
where: R_H = 1.097\times 10^{7}\,\text{m}^{-1}; n_2 > n_1.
where: h = 6.626\times 10^{-34}\,\text{J·s}.
where: Position–momentum uncertainty product floor.
where: c = 3\times 10^{8}\,\text{m/s}.
where: R = 0.0821\,\text{L·atm·K}^{-1}\!\text{·mol}^{-1} = 8.314\,\text{J·K}^{-1}\!\text{·mol}^{-1}.
where: Isothermal process.
where: Isobaric process. T in Kelvin.
where: Mixture of non-reacting gases.
where: Rate of effusion ∝ 1/√M at same T, P.
where: Average kinetic-molecular speed; M in kg/mol.
where: Real-gas correction; a (attraction), b (excluded volume).
where: Sign convention: w = work done ON the system; q = heat absorbed BY system.
where: \Delta n_g = (n_{\text{gas, products}} - n_{\text{gas, reactants}}).
where: Path-independence of state functions.
where: \Delta G < 0 ⇒ spontaneous at constant T, P.
where: K = thermodynamic equilibrium constant.
where: Ideal gas; reversible isothermal.
where: For phase change: \Delta S = \Delta H_{\text{fus/vap}}/T.
where: \Delta n_g = moles gaseous products – moles gaseous reactants.
where: Q < K → forward; Q = K → equilibrium; Q > K → reverse.
where: α = degree of dissociation, c = concentration.
where: pH + pOH = 14 at 25 °C.
where: Buffer solution pH; valid when α small.
where: s = molar solubility.
where: n = number of electrons transferred (or H⁺/OH⁻ for acid–base).
where: n = n-factor of the species.
where: At endpoint of acid–base or redox titration.
where: Vapour pressure of an ideal binary solution.
where: Colligative property.
where: K_b = ebullioscopic constant; i = van 't Hoff factor.
where: K_f = cryoscopic constant.
where: C = molar concentration; T in Kelvin.
where: n = number of particles formed; α = degree.
where: Both half-cells in reduction-potential convention.
where: n = electrons transferred; Q = reaction quotient.
where: F = 96485 C/mol; n = electrons transferred.
where: Mass deposited at electrode; Z = electrochemical equivalent.
where: κ in S/cm; C in mol/L; Λ_m in S·cm²/mol.
where: Independent migration of ions at infinite dilution.
where: Order = x+y; determined experimentally.
where: k has units of mol·L⁻¹·s⁻¹.
where: Half-life independent of initial concentration.
where: A = pre-exponential factor; E_a = activation energy.
where: Z = atoms/unit cell; a = edge length; M = molar mass.
where: FCC/CCP = 74%, BCC = 68%, SC = 52.4%.
where: Atoms touch along the face diagonal.
where: Atoms touch along the body diagonal.
where: Empirical; log–log plot is linear.
where: Monolayer adsorption; saturates at high P.
where: CN = coordination number. Sidgwick's rule.
where: n = unpaired electrons.
where: Δ_o = octahedral field splitting energy.
where: S_N1: 3°>2°>1°·CH₃; S_N2: opposite order.
where: l = path length (dm); c = concentration (g/mL).
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CBSE-12-CHEM-CH1
Outcome: Molarity, molality, mole fraction
Constants: Volume must be in litres; Solvent mass must be in kg; Mole fractions sum to 1
Trap: Do not use solution mass where solvent mass is required for molality.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 1 > formulas and constants locator metadata.
CBSE-12-CHEM-CH1
Outcome: Raoult law, partial pressure, and vapor composition
Constants: M(CHCl3) = 119.5 g mol^-1; M(CH2Cl2) = 85.0 g mol^-1; Use liquid mole fractions for partial pressures
Trap: Do not use mass fraction where mole fraction is required.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 1 > formulas and constants locator metadata.
CBSE-12-CHEM-CH1
Outcome: Ebullioscopy, molality, and molar mass
Constants: Kb(water) = 0.512 K kg mol^-1; m uses kg of solvent; Delta Tb is added to Tb0
Trap: Do not use solution mass instead of solvent mass.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 1 > formulas and constants locator metadata.
CBSE-12-CHEM-CH2
Outcome: Nernst equation and reaction quotient
Constants: F = 96485 C mol^-1; R = 8.314 J mol^-1 K^-1; 0.0591 V applies at 298 K
Trap: A flipped reaction quotient reverses the sign of the correction.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 2 > electrochemical cells and Nernst locator metadata.
CBSE-12-CHEM-CH2
Outcome: Limiting molar conductivity and weak electrolyte dissociation
Constants: lambda0(H+) = 349.6 S cm2 mol^-1; lambda0(CH3COO-) = 40.9 S cm2 mol^-1; alpha is dimensionless
Trap: Do not use measured Lambda_m as Lambda_m0 for weak electrolytes.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 2 > electrochemical cells and Nernst locator metadata.
CBSE-12-CHEM-CH2
Outcome: Faraday laws, charge, and deposited mass
Constants: F = 96485 C mol^-1; n = electrons in the half-reaction; time must be in seconds
Trap: Do not forget to divide by electron count n for multivalent ions.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 2 > electrochemical cells and Nernst locator metadata.
CBSE-12-CHEM-CH3
Outcome: Integrated first-order rate law
Constants: 2.303 converts ln to log10; 0.693 = ln 2; k has unit s^-1 for first order
Trap: First-order half-life is independent of starting concentration.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 3 > integrated rate laws locator metadata.
CBSE-12-CHEM-CH4
Outcome: d-electron count and unpaired electrons
Constants: n = unpaired electrons; BM = Bohr magneton; Oxidation state fixes d-electron count
Trap: Count d electrons after removing ns electrons first for transition-metal cations.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 4 > d/f-block trends locator metadata.
CBSE-12-CHEM-CH5
Outcome: Octahedral/tetrahedral splitting and spin state
Constants: Octahedral: t2g lower, eg higher; Tetrahedral order is inverted; Strong field favours low spin when pairing wins
Trap: Do not apply octahedral orbital order directly to tetrahedral complexes.
Source locator: NCERT Class XII Chemistry Part 1 > Chapter 5 > coordination compounds locator metadata.