CHEMISTRY

JEE Chemistry Formula Sheet

A curated, chapter-wise reference of Chemistry formulas, optimized for JEE Mains & Advanced preparation. Download printable PDF sheets for offline study.

Exam suite:

1. Basic Concepts

Mole Concept

Mole Calculations

M A
n=wMn = \frac{w}{M}
n=NNAn = \frac{N}{N_A}
n=VSTP (in L)22.7n = \frac{V_{STP} \text{ (in L)}}{22.7}
Parameters & Definitions

ww is mass of substance, MM is molar mass, NN is count of particles, NA6.022×1023N_A \approx 6.022 \times 10^{23} is Avogadro's number, and VSTPV_{STP} is volume of gas at standard temperature and pressure.

Basic relationships to calculate the number of moles (nn) from mass, number of particles, or gas volume at STP.

Molarity, Molality and Mole Fraction

Molarity, Molality and Mole Fraction

M A
M=nsoluteVsolution (in L)M = \frac{n_{solute}}{V_{solution} \text{ (in L)}}
m=nsoluteWsolvent (in kg)m = \frac{n_{solute}}{W_{solvent} \text{ (in kg)}}
xA=nAnA+nBx_A = \frac{n_A}{n_A + n_B}
Parameters & Definitions

MM is molarity, mm is molality, xAx_A is mole fraction of component A, nn represents moles, VV represents volume, and WW represents solvent mass.

Formulas to express concentration of solute in a solution.

2. Atomic Structure

Bohr Model & Spectral Lines

Rydberg Formula for Spectral Lines

M A
νˉ=1λ=RHZ2(1n121n22)\bar{\nu} = \frac{1}{\lambda} = R_H Z^2 \left( \frac{1}{n_1^2} - \frac{1}{n_2^2} \right)
Parameters & Definitions

νˉ\bar{\nu} is wave number, λ\lambda is wavelength, RH1.09677×107 m1R_H \approx 1.09677 \times 10^7 \text{ m}^{-1} is Rydberg constant, ZZ is atomic number, and n1,n2n_1, n_2 are principal quantum numbers (n2>n1n_2 > n_1).

Formula to calculate the wavelength or wave number of spectral lines emitted during electronic transitions in hydrogen-like atoms.

de Broglie Wavelength & Uncertainty

de Broglie Wavelength and Heisenberg Uncertainty Principle

M A
λ=hmv=hp\lambda = \frac{h}{mv} = \frac{h}{p}
ΔxΔph4π\Delta x \cdot \Delta p \ge \frac{h}{4\pi}
Parameters & Definitions

λ\lambda is de Broglie wavelength, hh is Planck's constant, mm is mass, vv is velocity, pp is momentum, Δx\Delta x is position uncertainty, and Δp\Delta p is momentum uncertainty.

Mathematical statements of wave-particle duality and the fundamental limit on simultaneous measurement precision.

3. Chemical Bonding

VSEPR Shapes & Hybridization

Steric Number and Hybridization

M A
SN=12[V+MC+A]SN = \frac{1}{2} [ V + M - C + A ]
Parameters & Definitions

VV is the number of valence electrons on the central atom, MM is the number of monovalent atoms bonded to it, CC is the charge of the cation, and AA is the charge of the anion.

Formula to calculate the steric number (SNSN) of a central atom to determine its hybridization and geometry.

Molecular Orbital Theory

Bond Order (Molecular Orbital Theory)

M A
Bond Order=NbNa2\text{Bond Order} = \frac{N_b - N_a}{2}
Parameters & Definitions

NbN_b is the number of electrons in bonding molecular orbitals, and NaN_a is the number of electrons in antibonding molecular orbitals.

Formulas to calculate bond order, predicting stability and bond length comparison.

Dipole Moment

Dipole Moment

M A
μ=q×d\mu = q \times d
Parameters & Definitions

μ\mu is dipole moment, qq is magnitude of charge, and dd is separation distance.

Mathematical definition of molecular dipole moment for a charge separation.

4. States of Matter

Ideal Gas Equation

Ideal Gas Equation

A
PV=nRTPV = nRT
Parameters & Definitions

PP is pressure, VV is volume, nn is moles, TT is temperature, and RR is gas constant.

Equation of state for an ideal gas.

van der Waals Equation

van der Waals Equation

A
(P+an2V2)(Vnb)=nRT\left( P + \frac{an^2}{V^2} \right)(V - nb) = nRT
Parameters & Definitions

PP is pressure, VV is volume, nn is moles, TT is temperature, RR is gas constant, aa is molecular attraction factor, and bb is excluded volume factor.

Real gas equation incorporating molecular attraction and volume corrections.

Dalton's Partial Pressures

Dalton's Law

A
Pi=xiPtotalP_i = x_i P_{total}
Parameters & Definitions

PiP_i is partial pressure of gas ii, xix_i is its mole fraction, and PtotalP_{total} is total pressure.

Partial pressures in gas mixtures.

Graham's Diffusion Law

Graham's Law of Diffusion

A
r1r2=M2M1=d2d1\frac{r_1}{r_2} = \sqrt{\frac{M_2}{M_1}} = \sqrt{\frac{d_2}{d_1}}
Parameters & Definitions

r1,r2r_1, r_2 are diffusion rates, M1,M2M_1, M_2 are molar masses, and d1,d2d_1, d_2 are densities.

Relative rates of diffusion/effusion.

5. Thermodynamics

First Law & Expansion Work

First Law and Expansion Work

M A
ΔU=q+w\Delta U = q + w
wrev=2.303nRTlog10(V2V1)w_{rev} = -2.303 nRT \log_{10}\left(\frac{V_2}{V_1}\right)
Parameters & Definitions

ΔU\Delta U is change in internal energy, qq is heat exchanged, ww is work, nn is moles, RR is gas constant, TT is temperature, and V1,V2V_1, V_2 are volumes.

Energy conservation equation and reversible expansion work formulas for gas systems.

Enthalpy & Hess's Law

Enthalpy and Internal Energy Relation

M A
ΔH=ΔU+ΔngRT\Delta H = \Delta U + \Delta n_g RT
Parameters & Definitions

ΔH\Delta H is change in enthalpy, ΔU\Delta U is change in internal energy, Δng\Delta n_g is change in gaseous moles, RR is gas constant, and TT is temperature.

Enthalpy change relation for gaseous reactions.

Entropy & Second Law

Entropy Change and Second Law of Thermodynamics

M A
ΔS=qrevT\Delta S = \frac{q_{\text{rev}}}{T}
ΔStotal=ΔSsystem+ΔSsurroundings0\Delta S_{\text{total}} = \Delta S_{\text{system}} + \Delta S_{\text{surroundings}} \ge 0
Parameters & Definitions

ΔS\Delta S is the change in entropy, qrevq_{\text{rev}} is the heat exchanged reversibly, and TT is the absolute temperature in Kelvin.

Definition of entropy change and the total entropy criterion for a spontaneous process.

Gibbs Energy & Equilibrium

Gibbs Free Energy and Spontaneity

M A
ΔG=ΔHTΔS\Delta G = \Delta H - T\Delta S
ΔG=2.303RTlog10Keq\Delta G^\circ = -2.303 RT \log_{10} K_{eq}
Parameters & Definitions

ΔG\Delta G is Gibbs free energy change, ΔG\Delta G^\circ is standard Gibbs energy change, ΔH\Delta H is enthalpy change, TT is absolute temperature, ΔS\Delta S is entropy change, and KeqK_{eq} is equilibrium constant.

Definition of Gibbs free energy change and standard Gibbs energy relation.

6. Chemical Equilibrium

Kp and Kc Relations

Relationship Between Kp and Kc

M A
Kp=Kc(RT)ΔngK_p = K_c (RT)^{\Delta n_g}
Parameters & Definitions

Kp,KcK_p, K_c are equilibrium constants, RR is gas constant, TT is temperature, and Δng\Delta n_g is change in moles of gaseous components.

Mathematical formula linking pressure-based and concentration-based equilibrium constants.

Le Chatelier's Principle

Reaction Quotient Shift Direction

M A
Qc<Kc    shifts right (forward)Q_c < K_c \implies \text{shifts right (forward)}
Qc>Kc    shifts left (backward)Q_c > K_c \implies \text{shifts left (backward)}
Qc=Kc    at equilibriumQ_c = K_c \implies \text{at equilibrium}
Parameters & Definitions

QcQ_c is the reaction quotient, and KcK_c is the equilibrium constant.

Determines the shift direction of equilibrium by comparing the reaction quotient QcQ_c and the equilibrium constant KcK_c.

Van 't Hoff Reaction Isochore

M A
ln(K2K1)=ΔHR(1T11T2)\ln\left(\frac{K_2}{K_1}\right) = \frac{\Delta H^\circ}{R} \left( \frac{1}{T_1} - \frac{1}{T_2} \right)
Parameters & Definitions

K1,K2K_1, K_2 are equilibrium constants at temperatures T1,T2T_1, T_2, ΔH\Delta H^\circ is standard enthalpy of reaction, and RR is gas constant.

Relates the equilibrium constants at two different temperatures to the standard enthalpy of reaction.

7. Ionic Equilibrium

pH Scale

pH Definition

M A
pH=log10[H+]\text{pH} = -\log_{10}[H^+]
Parameters & Definitions

[H+][H^+] is the concentration of hydronium ions.

Mathematical definition of the pH scale.

Henderson Buffer Equation

Henderson-Hasselbalch Buffer Equations

M A
pH=pKa+log10([Conjugate Base][Acid])\text{pH} = pK_a + \log_{10}\left( \frac{[\text{Conjugate Base}]}{[\text{Acid}]} \right)
pOH=pKb+log10([Conjugate Acid][Base])\text{pOH} = pK_b + \log_{10}\left( \frac{[\text{Conjugate Acid}]}{[\text{Base}]} \right)
Parameters & Definitions

pKa=logKapK_a = -\log K_a, pKb=logKbpK_b = -\log K_b, and brackets denote molar concentrations.

Formulas for calculating pH of acidic/basic buffer solutions.

Solubility Product (Ksp)

Solubility Product Constant

M A
AxByxAy++yBx    Ksp=xxyySx+yA_x B_y \rightleftharpoons xA^{y+} + yB^{x-} \implies K_{sp} = x^x y^y S^{x+y}
Parameters & Definitions

KspK_{sp} is solubility product, SS is molar solubility of salt, and x,yx, y are stoichiometric coefficients of cations and anions.

Relationship between solubility (SS) and solubility product (KspK_{sp}) for standard electrolyte salts.

8. Redox Reactions

Oxidation States & Balancing

Sum of Oxidation States

M A
iniO.S.i=Net Charge\sum_{i} n_i \cdot \text{O.S.}_i = \text{Net Charge}
Parameters & Definitions

nin_i is the number of atoms of species ii, O.S.i\text{O.S.}_i is their oxidation state, and Net Charge\text{Net Charge} is the overall charge.

Rule stating the sum of oxidation numbers of all atoms in a molecule/ion equals its total electrical charge.

Equivalent Weight of Redox Agent

M A
E=Molar Massn-factorE = \frac{\text{Molar Mass}}{\text{n-factor}}
Parameters & Definitions

EE is equivalent weight, Molar Mass\text{Molar Mass} is the molecular weight, and n-factor\text{n-factor} is the number of electrons gained or lost per mole of reactant.

Definition of equivalent mass of an oxidizing or reducing agent in a redox reaction.

9. Electrochemistry

Conductance & Kohlrausch Law

Conductivity, Molar Conductivity and Kohlrausch's Law

M A
Λm=κ×1000C\Lambda_m = \frac{\kappa \times 1000}{C}
Λm=ν+λ++νλ\Lambda_m^\circ = \nu_+ \lambda_+^\circ + \nu_- \lambda_-^\circ
Parameters & Definitions

Λm\Lambda_m is molar conductivity, κ\kappa is specific conductivity, CC is molar concentration, Λm\Lambda_m^\circ is limiting molar conductivity, and ν+,ν\nu_+, \nu_- are ion counts with limiting conductances λ+,λ\lambda_+^\circ, \lambda_-^\circ.

Expressions for molar conductivity and its value at infinite dilution.

Debye-Hückel-Onsager Equation

M A
Λm=ΛmAC\Lambda_m = \Lambda_m^\circ - A \sqrt{C}
Parameters & Definitions

Λm\Lambda_m is molar conductivity, Λm\Lambda_m^\circ is limiting molar conductivity at infinite dilution, CC is electrolyte concentration, and AA is a constant depending on solvent, charge type, and temperature.

Describes the concentration dependence of molar conductivity for strong electrolytes.

Galvanic Cells & Nernst Equation

Nernst Equation

M A
Ecell=Ecell0.0591nlog10Qat 298 KE_{cell} = E^\circ_{cell} - \frac{0.0591}{n} \log_{10} Q \quad \text{at } 298\text{ K}
Parameters & Definitions

EcellE_{cell} is cell potential, EcellE^\circ_{cell} is standard potential, nn is number of electrons transferred, and QQ is reaction quotient.

Calculates cell potential under non-standard conditions.

Gibbs Energy & Cell Potential

Gibbs Free Energy and EMF

M A
ΔG=nFEcell\Delta G = -n F E_{cell}
Parameters & Definitions

ΔG\Delta G is Gibbs free energy change, nn is electrons transferred, F96500 C mol1F \approx 96500 \text{ C mol}^{-1} is Faraday constant, and EcellE_{cell} is cell potential.

Links cell potential to Gibbs free energy change.

Electrolysis & Faraday's Laws

Faraday's Laws of Electrolysis

M A
w=ZIt=(EeqF)Itw = Z I t = \left( \frac{E_{eq}}{F} \right) I t
Equivalent Moles=I×t96500\text{Equivalent Moles} = \frac{I \times t}{96500}
Parameters & Definitions

ww is mass deposited, ZZ is electrochemical equivalent, II is current, tt is time, EeqE_{eq} is equivalent weight of substance, and FF is Faraday constant.

Quantitative mass yield of substances discharged at electrodes during electrolysis.

10. Solutions

Henry & Raoult Laws

Henry's Law and Raoult's Law

M A
p=KHxp = K_H x
Ptotal=PAxA+PBxBP_{total} = P_A^\circ x_A + P_B^\circ x_B
Parameters & Definitions

p,Ptotalp, P_{total} are vapor pressures, KHK_H is Henry's constant, x,xA,xBx, x_A, x_B are mole fractions, and PA,PBP_A^\circ, P_B^\circ are pure component vapor pressures.

Equations showing vapor pressures of solute gases and volatile liquid solutions.

Vapor Pressure Lowering & Osmotic Pressure

Vapor Pressure and Osmotic Pressure Equations

M A
PPP=ixsolute\frac{P^\circ - P}{P^\circ} = i x_{solute}
π=iCRT\pi = i C R T
Parameters & Definitions

P,PP^\circ, P are vapor pressures, ii is van 't Hoff factor, xsolutex_{solute} is mole fraction of solute, π\pi is osmotic pressure, CC is molarity, RR is gas constant, and TT is temperature.

Formulas to calculate vapor pressure lowering and osmotic pressure.

van 't Hoff Factor and Degree of Dissociation/Association

M A
α=i1n1(Dissociation)\alpha = \frac{i - 1}{n - 1} \quad \text{(Dissociation)}
β=1i11/n(Association)\beta = \frac{1 - i}{1 - 1/n} \quad \text{(Association)}
Parameters & Definitions

ii is the van 't Hoff factor, α\alpha is the degree of dissociation, β\beta is the degree of association, and nn is the number of ions/molecules formed or associated per reactant unit.

Relates the van 't Hoff factor (ii) to the degree of electrolyte dissociation (α\alpha) and association (β\beta).

Boiling Elevation & Freezing Depression

Boiling and Freezing Point Shifts

M A
ΔTb=iKbm\Delta T_b = i K_b m
ΔTf=iKfm\Delta T_f = i K_f m
Parameters & Definitions

ΔTb,ΔTf\Delta T_b, \Delta T_f are temperature shifts, ii is van 't Hoff factor, Kb,KfK_b, K_f are molal constants, and mm is molality of solution.

Formulas to calculate boiling point elevation and freezing point depression.

11. Chemical Kinetics

Reaction Orders & Integrated Rate Laws

Integrated Rate Laws

M A
[A]t=[A]0kt(Zero-Order)[A]_t = [A]_0 - kt \quad \text{(Zero-Order)}
k=2.303tlog10([A]0[A]t)(First-Order)k = \frac{2.303}{t} \log_{10}\left(\frac{[A]_0}{[A]_t}\right) \quad \text{(First-Order)}
Parameters & Definitions

[A]0[A]_0 is initial concentration, [A]t[A]_t is concentration at time tt, and kk is rate constant.

Rate constant relations for zero-order and first-order chemical reactions.

Half-life of Reaction

Half-Lives

M A
t1/2=[A]02k(Zero-Order)t_{1/2} = \frac{[A]_0}{2k} \quad \text{(Zero-Order)}
t1/2=0.693k(First-Order)t_{1/2} = \frac{0.693}{k} \quad \text{(First-Order)}
Parameters & Definitions

[A]0[A]_0 is initial concentration, kk is rate constant, and t1/2t_{1/2} is half-life.

Half-life relations for zero-order and first-order chemical reactions.

Temperature Dependence & Arrhenius Equation

Arrhenius Equation for Temperature Dependence

M A
k=AeEaRT    log10(k2k1)=Ea2.303R(T2T1T1T2)k = A e^{-\frac{E_a}{RT}} \implies \log_{10}\left(\frac{k_2}{k_1}\right) = \frac{E_a}{2.303 R} \left( \frac{T_2 - T_1}{T_1 T_2} \right)
Parameters & Definitions

k,k1,k2k, k_1, k_2 are rate constants, AA is frequency factor, EaE_a is activation energy, RR is gas constant, and T,T1,T2T, T_1, T_2 are absolute temperatures.

Shows how chemical rate constant varies with temperature based on activation energy.

12. Solid State

Crystal Systems & Voids

Crystal Density and Packing Efficiency

A
ρ=ZMa3NA\rho = \frac{Z \cdot M}{a^3 \cdot N_A}
Packing Fraction=Z43πr3a3(FCC = 74%, BCC = 68%, Simple = 52.4%)\text{Packing Fraction} = \frac{Z \cdot \frac{4}{3}\pi r^3}{a^3} \quad \text{(FCC = 74\%, BCC = 68\%, Simple = 52.4\%)}
Parameters & Definitions

ρ\rho is the density, ZZ is the number of atoms per unit cell, MM is the molar mass, aa is the edge length, NAN_A is Avogadro's number, and rr is the atomic radius.

Formulas to calculate unit cell density and packing fraction in cubic crystal lattices.

Density of Unit Cell

Density of a Cubic Unit Cell

A
ρ=zMNAa3\rho = \frac{z M}{N_A a^3}
Parameters & Definitions

ρ\rho is density, zz is number of atoms per unit cell, MM is molar mass, NAN_A is Avogadro's number, and aa is edge length of the cubic cell.

Theoretical density of a crystalline solid based on lattice parameters.

13. Surface Chemistry

Adsorption & Freundlich Isotherm

Freundlich Adsorption Isotherm

A
xm=kP1/n(1n1)\frac{x}{m} = k P^{1/n} \quad \left(\frac{1}{n} \le 1\right)
Parameters & Definitions

xx is mass of adsorbate, mm is mass of adsorbent, PP is pressure, and k,nk, n are temperature-dependent constants.

Empirical relationship for the adsorption of gas on solid adsorbent surfaces.

Colloidal States & Properties

Coagulation Value

A
Coagulation Value=Millimoles of electrolyteVolume of colloid in Litres\text{Coagulation Value} = \frac{\text{Millimoles of electrolyte}}{\text{Volume of colloid in Litres}}
Parameters & Definitions

Coagulation Value\text{Coagulation Value} is expressed in millimoles per litre of colloid.

Minimum concentration of an electrolyte required to cause coagulation of a sol.

Gold Number

A
Gold Number=mg of protective colloid for 10 mL gold sol against 1 mL of 10% NaCl\text{Gold Number} = \text{mg of protective colloid for } 10\text{ mL gold sol against } 1\text{ mL of } 10\% \text{ NaCl}
Parameters & Definitions

Gold Number\text{Gold Number} is measured in milligrams.

Defines the protective power of a lyophilic colloid. A lower gold number indicates better protection.

14. Periodic Table

Periodic Trends in Properties

Effective Nuclear Charge

M A
Zeff=ZσZ_{\text{eff}} = Z - \sigma
Parameters & Definitions

ZeffZ_{\text{eff}} is the effective nuclear charge, ZZ is atomic number, and σ\sigma is the shielding constant.

Slater's rule equation for calculating the effective nuclear charge felt by valence electrons.

Pauling Electronegativity Difference

M A
χAχB=0.102ΔEwhere ΔE=Ed(AB)Ed(AA)Ed(BB)\chi_A - \chi_B = 0.102 \sqrt{\Delta_E} \quad \text{where } \Delta_E = E_{d(A-B)} - \sqrt{E_{d(A-A)} \cdot E_{d(B-B)}}
Parameters & Definitions

χA,χB\chi_A, \chi_B are electronegativities, and Ed(AB)E_{d(A-B)} represents the bond dissociation energy of ABA-B bond.

Estimates the electronegativity difference between two bonded atoms using bond dissociation energies in kJ/mol.

15. Hydrogen

Properties & Compounds of Hydrogen

Volume Strength of Hydrogen Peroxide

A
Volume Strength=11.2×Molarity\text{Volume Strength} = 11.2 \times \text{Molarity}
Volume Strength=5.6×Normality\text{Volume Strength} = 5.6 \times \text{Normality}
Parameters & Definitions

Volume strength is the volume of O2O_2 (in L) released by 1 L of H2O2H_2O_2 at STP; Molarity and Normality represent solution concentrations.

Relations between volume strength, molarity, and normality of H2O2H_2O_2 solution.

16. s-Block Elements

Alkali & Alkaline Earth Metals

Solvay Process Net Reaction

A
2NaCl+CaCO3Na2CO3+CaCl22\text{NaCl} + \text{CaCO}_3 \longrightarrow \text{Na}_2\text{CO}_3 + \text{CaCl}_2
Parameters & Definitions

Reactants are sodium chloride and calcium carbonate; products are sodium carbonate and calcium chloride.

Net overall reaction representing the manufacturing of sodium carbonate via the Solvay process.

Plaster of Paris Preparation

A
CaSO42H2O120CCaSO412H2O+32H2O\text{CaSO}_4 \cdot 2\text{H}_2\text{O} \xrightarrow{120^\circ\text{C}} \text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O} + \frac{3}{2}\text{H}_2\text{O}
Parameters & Definitions

Reactant is Gypsum, product is Plaster of Paris and steam.

Thermal decomposition of Gypsum to Plaster of Paris.

17. p-Block Elements

General Trends in Groups 13-18

Borax Bead Thermal Decomposition

M A
Na2B4O710H2OΔNa2B4O7Δ2NaBO2+B2O3\text{Na}_2\text{B}_4\text{O}_7 \cdot 10\text{H}_2\text{O} \xrightarrow{\Delta} \text{Na}_2\text{B}_4\text{O}_7 \xrightarrow{\Delta} 2\text{NaBO}_2 + \text{B}_2\text{O}_3
Parameters & Definitions

NaBO2\text{NaBO}_2 is sodium metaborate and B2O3\text{B}_2\text{O}_3 is boric anhydride (boron trioxide).

Thermal swelling and decomposition of borax to form sodium metaborate and boric anhydride.

Xenon Tetrafluoride Hydrolysis

M A
6XeF4+12H2O4Xe+2XeO3+24HF+3O26\text{XeF}_4 + 12\text{H}_2\text{O} \longrightarrow 4\text{Xe} + 2\text{XeO}_3 + 24\text{HF} + 3\text{O}_2
Parameters & Definitions

XeF4\text{XeF}_4 is xenon tetrafluoride, and XeO3\text{XeO}_3 is explosive xenon trioxide.

Complete hydrolysis reaction of xenon tetrafluoride producing xenon gas and xenon trioxide.

18. d- & f-Block Elements

First-Row Transition Metals

Chromate-Dichromate pH-Dependent Equilibrium

M A
2CrO42+2H+Cr2O72+H2O2\text{CrO}_4^{2-} + 2\text{H}^+ \rightleftharpoons \text{Cr}_2\text{O}_7^{2-} + \text{H}_2\text{O}
Parameters & Definitions

CrO42\text{CrO}_4^{2-} is yellow chromate ion (stable in alkaline solution), and Cr2O72\text{Cr}_2\text{O}_7^{2-} is orange dichromate ion (stable in acidic solution).

Reversible pH-dependent equilibrium between yellow chromate and orange dichromate ions.

Dichromate Reduction in Acidic Medium

M A
Cr2O72+14H++6e2Cr3++7H2O\text{Cr}_2\text{O}_7^{2-} + 14\text{H}^+ + 6e^- \longrightarrow 2\text{Cr}^{3+} + 7\text{H}_2\text{O}
Parameters & Definitions

Cr3+\text{Cr}^{3+} is green chromic ion, and nn-factor of Cr2O72\text{Cr}_2\text{O}_7^{2-} is 6.

Half-reaction for the reduction of dichromate ion in acidic solution, where chromium is reduced from +6 to +3.

Spin-Only Magnetic Moment

Spin-Only Magnetic Moment Formula

M A
μspin=n(n+2) B.M.\mu_{spin} = \sqrt{n(n+2)} \text{ B.M.}
Parameters & Definitions

μspin\mu_{spin} is spin-only magnetic moment in Bohr Magnetons (B.M.), and nn is number of unpaired electrons.

Calculates magnetic moment of transition metal ions based on unpaired d-electrons.

Lanthanoids & Actinoids

Shielding Effectiveness Trend

M A
σ(4f)<σ(5d)<σ(5p)<σ(5s)\sigma(4f) < \sigma(5d) < \sigma(5p) < \sigma(5s)
Parameters & Definitions

σ\sigma is shielding constant of respective subshells.

Shielding constant comparison showing the poor shielding power of f-orbitals, which leads to lanthanoid contraction.

General Lanthanoid Configuration

M A
[Xe]4f1145d016s2[\text{Xe}] \, 4f^{1-14} \, 5d^{0-1} \, 6s^2
Parameters & Definitions

[Xe][\text{Xe}] is xenon noble gas core, 4f4f is filling inner f-orbital, 5d5d is transition d-orbital, and 6s6s is valence s-orbital.

General valence shell electronic configuration of the lanthanoid series elements.

19. Coordination Compounds

Nomenclature & Isomerism

Effective Atomic Number (EAN) Rule

M A
EAN=ZO.S.+2×C.N.\text{EAN} = Z - \text{O.S.} + 2 \times \text{C.N.}
Parameters & Definitions

ZZ is atomic number of metal, O.S.\text{O.S.} is oxidation state of metal, and C.N.\text{C.N.} is coordination number (number of coordinate bonds).

Calculates the effective atomic number of a central metal atom/ion in a coordination complex.

Valence Bond & Crystal Field Theory

CFSE for Octahedral Complexes

M A
CFSE=(0.4nt2g+0.6neg)Δo+mP\text{CFSE} = \left( -0.4 n_{t_{2g}} + 0.6 n_{e_g} \right) \Delta_o + m P
Parameters & Definitions

CFSE is Crystal Field Stabilization Energy, nt2gn_{t_{2g}} is number of electrons in t2gt_{2g} orbitals, negn_{e_g} is number of electrons in ege_g orbitals, Δo\Delta_o is octahedral splitting parameter, PP is pairing energy, and mm is number of paired electron configurations.

Stabilization energy calculation of d-electrons in octahedral crystal fields.

20. Metallurgy

Principles & Extraction Processes

Ellingham Diagram Thermodynamic Condition

A
ΔG=ΔHTΔS<0\Delta G^\circ = \Delta H^\circ - T\Delta S^\circ < 0
Parameters & Definitions

ΔG\Delta G^\circ is standard Gibbs free energy change, ΔH\Delta H^\circ is standard enthalpy change, TT is temperature, and ΔS\Delta S^\circ is standard entropy change.

Thermodynamic spontaneity condition governing the reduction of metal oxides using carbon or other metals.

Mond Process for Nickel Refining

A
Ni(impure)+4CO330350 KNi(CO)4450470 KNi(pure)+4CO\text{Ni} (\text{impure}) + 4\text{CO} \xrightarrow{330-350\text{ K}} \text{Ni(CO)}_4 \xrightarrow{450-470\text{ K}} \text{Ni} (\text{pure}) + 4\text{CO}
Parameters & Definitions

Ni(CO)4\text{Ni(CO)}_4 is volatile nickel tetracarbonyl complex.

Two-step gaseous carbonyl metallurgy process used for the purification of nickel metal.

21. Organic Purification

Purification Methods (Distillation, Chromatography)

Steam Distillation Mass Ratio

M A
w1w2=p1M1p2M2\frac{w_1}{w_2} = \frac{p_1 M_1}{p_2 M_2}
Parameters & Definitions

w1,w2w_1, w_2 are masses of organic compound and water, p1,p2p_1, p_2 are vapor pressures at distillation temperature, and M1,M2M_1, M_2 are molecular weights.

Formula relating the masses of the distilled organic liquid and water to their vapor pressures and molecular weights.

Chromatography Retention Factor

M A
Rf=Distance traveled by substance from baselineDistance traveled by solvent front from baselineR_f = \frac{\text{Distance traveled by substance from baseline}}{\text{Distance traveled by solvent front from baseline}}
Parameters & Definitions

RfR_f is a dimensionless fraction, representing chromatographic mobility.

Defines the retardation factor (RfR_f) of a compound in thin-layer or paper chromatography.

Qualitative & Quantitative Organic Analysis

Nitrogen Percentage by Kjeldahl's Method

M A
% N=1.4×N×Vw\% \text{ N} = \frac{1.4 \times N \times V}{w}
Parameters & Definitions

NN is normality of acid, VV is volume of acid consumed by ammonia (in mL), and ww is mass of organic sample analyzed (in grams).

Quantitative estimation of nitrogen percentage in organic samples.

Nitrogen Percentage by Dumas' Method

M A
% N=28×VSTP×10022400×w\% \text{ N} = \frac{28 \times V_{STP} \times 100}{22400 \times w}
Parameters & Definitions

VSTPV_{STP} is volume of nitrogen collected at STP in mL, and ww is mass of organic compound in grams.

Quantitative estimation of nitrogen by measuring volume of nitrogen collected at STP.

Halogen Percentage by Carius Method

M A
% Cl=35.5143.5×mAgClw×100\% \text{ Cl} = \frac{35.5}{143.5} \times \frac{m_{AgCl}}{w} \times 100
% Br=80188×mAgBrw×100\% \text{ Br} = \frac{80}{188} \times \frac{m_{AgBr}}{w} \times 100
% I=127235×mAgIw×100\% \text{ I} = \frac{127}{235} \times \frac{m_{AgI}}{w} \times 100
Parameters & Definitions

mAgCl,mAgBr,mAgIm_{AgCl}, m_{AgBr}, m_{AgI} are the masses of the respective silver halide precipitates formed (in grams), and ww is the mass of the organic compound analyzed.

Quantitative estimation of halogens (Chlorine, Bromine, Iodine) from silver halide precipitates.

Sulfur Percentage by Carius Method

M A
% S=32233×mBaSO4w×100\% \text{ S} = \frac{32}{233} \times \frac{m_{BaSO_4}}{w} \times 100
Parameters & Definitions

mBaSO4m_{BaSO_4} is the mass of the barium sulfate precipitate formed (in grams), and ww is the mass of the organic compound analyzed.

Quantitative estimation of sulfur by converting it to barium sulfate precipitate.

Phosphorus Percentage Estimation

M A
% P=62222×mMg2P2O7w×100\% \text{ P} = \frac{62}{222} \times \frac{m_{Mg_2P_2O_7}}{w} \times 100
Parameters & Definitions

mMg2P2O7m_{Mg_2P_2O_7} is the mass of magnesium pyrophosphate precipitate formed (in grams), and ww is the mass of the organic compound analyzed.

Quantitative estimation of phosphorus by precipitating it as magnesium pyrophosphate.

22. General Organic Chemistry

Nomenclature, Shapes & Isomerism

Specific Optical Rotation

M A
[α]λT=αobservedlc[\alpha]_\lambda^T = \frac{\alpha_{\text{observed}}}{l \cdot c}
Parameters & Definitions

[α]λT[\alpha]_\lambda^T is specific rotation, αobserved\alpha_{\text{observed}} is observed rotation in degrees, ll is tube path length in decimeters, and cc is concentration in g/mL.

Calculates specific optical rotation of an optically active substance in solution.

Stereoisomer Count for Unsymmetrical Molecules

M A
N=2nN = 2^n
Parameters & Definitions

NN is total number of stereoisomers, and nn is the number of chiral centers.

Calculates total number of stereoisomers (enantiomers + diastereomers) for an organic molecule with nn unsymmetric chiral centers.

Electronic Displacements & Reaction Intermediates

Acid Dissociation Constant and pKa Relation

M A
pKa=log10Ka    Acidic StrengthKa1pKapK_a = -\log_{10} K_a \implies \text{Acidic Strength} \propto K_a \propto \frac{1}{pK_a}
Parameters & Definitions

KaK_a is acid dissociation constant, and pKapK_a is the acid index (smaller pKapK_a means stronger acid).

Relates the acid dissociation constant (KaK_a) to its logarithmic index (pKapK_a), indicating relative organic acidity.

Hyperconjugation Alpha-Hydrogen Stability

M A
Carbocation/Radical StabilityNα-H\text{Carbocation/Radical Stability} \propto N_{\alpha\text{-H}}
Parameters & Definitions

Nα-HN_{\alpha\text{-H}} is the number of hydrogen atoms attached to carbons directly adjacent to the sp2 carbocation/radical center.

Relates the stability of carbocations and carbon free radicals to the number of hyperconjugable α\alpha-hydrogens.

23. Hydrocarbons

Alkanes, Alkenes, Alkynes & Aromatic Hydrocarbons

Double Bond Equivalent (Degree of Unsaturation)

M A
DBE=C+1H+XN2\text{DBE} = C + 1 - \frac{H + X - N}{2}
Parameters & Definitions

CC is number of carbon atoms, HH is hydrogen atoms, XX is halogen atoms, and NN is nitrogen atoms in the molecular formula.

Formula to calculate the number of rings or pi bonds in an organic molecule.

24. Haloalkanes & Haloarenes

Nucleophilic Substitution (SN1 & SN2) & Elimination

SN1 Reaction Kinetic Rate Law

M A
Rate=k[R-X]\text{Rate} = k [R\text{-}X]
Parameters & Definitions

kk is the rate constant, and [R-X][R\text{-}X] is the concentration of the alkyl halide substrate.

First-order rate equation governing unimolecular nucleophilic substitution (SN1S_N1) reactions.

SN2 Reaction Kinetic Rate Law

M A
Rate=k[R-X][Nu]\text{Rate} = k [R\text{-}X][Nu^-]
Parameters & Definitions

[R-X][R\text{-}X] is substrate concentration, and [Nu][Nu^-] is nucleophile concentration.

Second-order rate equation governing bimolecular nucleophilic substitution (SN2S_N2) reactions.

25. Alcohols, Phenols & Ethers

Preparations & Chemical Properties

Reimer-Tiemann Phenol Formylation

M A
C6H5OH+CHCl3+3NaOHo-C6H4(OH)CHO+3NaCl+2H2O\text{C}_6\text{H}_5\text{OH} + \text{CHCl}_3 + 3\text{NaOH} \longrightarrow o\text{-C}_6\text{H}_4(\text{OH})\text{CHO} + 3\text{NaCl} + 2\text{H}_2\text{O}
Parameters & Definitions

Reactants are phenol, chloroform, and sodium hydroxide; product is oo-salicylaldehyde.

Formylation of phenol to salicylaldehyde using chloroform and sodium hydroxide.

Hydroboration-Oxidation Net Reaction

M A
3R-CH=CH2+BH3H2O2/OH3R-CH2-CH2-OH+B(OH)33R\text{-CH=CH}_2 + \text{BH}_3 \xrightarrow{\text{H}_2\text{O}_2 / \text{OH}^-} 3R\text{-CH}_2\text{-CH}_2\text{-OH} + \text{B(OH)}_3
Parameters & Definitions

Reactants are alkene and borane, giving a primary alcohol and boric acid.

Anti-Markovnikov hydration of an alkene to form a primary alcohol via hydroboration and oxidation.

26. Aldehydes, Ketones & Carboxylic Acids

Nucleophilic Addition & Carbonyl Condensations

Aldol Self-Condensation Reaction

M A
2CH3-CHOdil. NaOHCH3-CH(OH)-CH2-CHOΔCH3-CH=CH-CHO+H2O2CH_3\text{-CHO} \xrightarrow{\text{dil. NaOH}} CH_3\text{-CH(OH)-CH}_2\text{-CHO} \xrightarrow{\Delta} CH_3\text{-CH=CH-CHO} + \text{H}_2\text{O}
Parameters & Definitions

Reactant is acetaldehyde; product is crotonaldehyde (but-2-enal).

Self-condensation of acetaldehyde in dilute base followed by dehydration to form crotonaldehyde (\alpha,\beta-unsaturated aldehyde).

Cannizzaro Reaction of Benzaldehyde

M A
2C6H5-CHO+NaOHC6H5-COONa+C6H5-CH2OH2\text{C}_6\text{H}_5\text{-CHO} + \text{NaOH} \longrightarrow \text{C}_6\text{H}_5\text{-COONa} + \text{C}_6\text{H}_5\text{-CH}_2\text{OH}
Parameters & Definitions

Reactant is benzaldehyde; products are sodium benzoate and benzyl alcohol.

Redox disproportional of non-enolizable aldehydes (e.g. benzaldehyde) in concentrated base.

27. Amines & Diazonium Salts

Basicity & Synthetic Reactions of Amines

Hoffmann Bromamide Degradation

M A
R-CONH2+Br2+4KOHR-NH2+K2CO3+2KBr+2H2OR\text{-CONH}_2 + \text{Br}_2 + 4\text{KOH} \longrightarrow R\text{-NH}_2 + \text{K}_2\text{CO}_3 + 2\text{KBr} + 2\text{H}_2\text{O}
Parameters & Definitions

R-CONH2R\text{-CONH}_2 is primary amide, and R-NH2R\text{-NH}_2 is primary amine product.

Degradation of an amide to a primary amine with one fewer carbon atom using bromine and base.

Carbylamine Primary Amine Test

M A
R-NH2+CHCl3+3KOHR-NC+3KCl+3H2OR\text{-NH}_2 + \text{CHCl}_3 + 3\text{KOH} \longrightarrow R\text{-NC} + 3\text{KCl} + 3\text{H}_2\text{O}
Parameters & Definitions

R-NH2R\text{-NH}_2 is primary amine, and R-NCR\text{-NC} is alkyl/aryl isocyanide.

Diagnostic test for primary amines (both aliphatic and aromatic) forming an offensively smelling isocyanide.

28. Biomolecules

Carbohydrates, Proteins & Nucleic Acids

Sucrose Acid Hydrolysis (Inversion of Cane Sugar)

M A
C12H22O11+H2OH+C6H12O6(D-glucose)+C6H12O6(D-fructose)\text{C}_{12}\text{H}_{22}\text{O}_{11} + \text{H}_2\text{O} \xrightarrow{\text{H}^+} \text{C}_6\text{H}_{12}\text{O}_6 \, (\text{D-glucose}) + \text{C}_6\text{H}_{12}\text{O}_6 \, (\text{D-fructose})
Parameters & Definitions

Specific rotation changes from +66.5+66.5^\circ (sucrose) to a net laevorotatory mixture of products.

Hydrolysis of sucrose to form D-glucose and D-fructose, resulting in inversion of optical rotation.

Isoelectric Point of Simple Amino Acids

M A
pI=pKa1+pKa22pI = \frac{pK_{a1} + pK_{a2}}{2}
Parameters & Definitions

pIpI is isoelectric point, pKa1pK_{a1} is logarithmic acid dissociation constant of carboxylic group, and pKa2pK_{a2} is that of the ammonium group.

Calculates the isoelectric point (pIpI) of an amino acid lacking an ionizable side chain.

29. Polymers

Polymers Structure & Polymerization

Nylon-6,6 Preparation

A
nHOOC-(CH2)4-COOH+nH2N-(CH2)6-NH2[-CO-(CH2)4-CONH-(CH2)6-NH-]n+2nH2On\text{HOOC-(CH}_2)_4\text{-COOH} + n\text{H}_2\text{N-(CH}_2)_6\text{-NH}_2 \longrightarrow \text{[-CO-(CH}_2)_4\text{-CONH-(CH}_2)_6\text{-NH-]} _n + 2n\text{H}_2\text{O}
Parameters & Definitions

Reactants are adipic acid and hexamethylenediamine; product is the Nylon-6,6 repeat unit.

Condensation copolymerization of adipic acid and hexamethylenediamine to form Nylon-6,6 polyamide.

Buna-S Synthetic Rubber Synthesis

A
nCH2=CH-CH=CH2+nC6H5-CH=CH2[-CH2-CH=CH-CH2-CH(C6H5)-CH2-]nn\text{CH}_2\text{=CH-CH=CH}_2 + n\text{C}_6\text{H}_5\text{-CH=CH}_2 \longrightarrow \text{[-CH}_2\text{-CH=CH-CH}_2\text{-CH(C}_6\text{H}_5)\text{-CH}_2\text{-]} _n
Parameters & Definitions

Reactants are butadiene and styrene; product is butadiene-styrene copolymer.

Addition copolymerization of buta-1,3-diene and styrene in 3:1 ratio to form Buna-S elastomer.

30. Everyday Chemistry

Medicines, Food Preservatives & Soaps

Saponification of Tristearin (Soap Formation)

A
(C17H35COO)3C3H5+3NaOH3C17H35COONa+C3H5(OH)3(\text{C}_{17}\text{H}_{35}\text{COO})_3\text{C}_3\text{H}_5 + 3\text{NaOH} \longrightarrow 3\text{C}_{17}\text{H}_{35}\text{COONa} + \text{C}_3\text{H}_5(\text{OH})_3
Parameters & Definitions

C17H35COONa\text{C}_{17}\text{H}_{35}\text{COONa} is sodium stearate (soap) and C3H5(OH)3\text{C}_3\text{H}_5(\text{OH})_3 is glycerol.

Alkali hydrolysis of tristearin fat using sodium hydroxide to yield sodium stearate soap and glycerol.

Aspirin Preparation (Acetylation of Salicylic Acid)

A
o-HOC6H4COOH+(CH3CO)2Oo-CH3COOC6H4COOH+CH3COOHo\text{-HOC}_6\text{H}_4\text{COOH} + (\text{CH}_3\text{CO})_2\text{O} \longrightarrow o\text{-CH}_3\text{COOC}_6\text{H}_4\text{COOH} + \text{CH}_3\text{COOH}
Parameters & Definitions

Reactants are salicylic acid and acetic anhydride; products are aspirin and acetic acid.

Acetylation of salicylic acid's phenolic hydroxyl group using acetic anhydride to form acetylsalicylic acid (Aspirin).

31. Environmental Chemistry

Environmental Pollutants & Green Chemistry

Acid Rain Sulfuric Acid Formation

A
2SO2+O2+2H2O2H2SO42\text{SO}_2 + \text{O}_2 + 2\text{H}_2\text{O} \longrightarrow 2\text{H}_2\text{SO}_4
Parameters & Definitions

Reactants are sulfur dioxide gas, oxygen, and atmospheric water vapor; product is sulfuric acid.

Atmospheric oxidation of sulfur dioxide in water droplets leading to sulfuric acid formation in acid rain.

Biochemical Oxygen Demand (BOD)

A
BOD=Clean Water(<5 ppm),Polluted Water(17 ppm)\text{BOD} = \text{Clean Water} \, (< 5 \text{ ppm}), \quad \text{Polluted Water} \, (\ge 17 \text{ ppm})
Parameters & Definitions

BOD is measured in parts per million (ppm) or mg/L.

Measure of water pollution denoting the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material.

32. Practical Chemistry

Qualitative Tests & Salt Analysis

Prussian Blue Complex Formation (Lassaigne's Test)

M A
4Fe3++3[Fe(CN)6]4Fe4[Fe(CN)6]34\text{Fe}^{3+} + 3[\text{Fe(CN)}_6]^{4-} \longrightarrow \text{Fe}_4[\text{Fe(CN)}_6]_3
Parameters & Definitions

Fe4[Fe(CN)6]3\text{Fe}_4[\text{Fe(CN)}_6]_3 is ferric ferrocyanide (Prussian blue precipitate).

Confirmatory test reaction for nitrogen in organic compounds, yielding a characteristic Prussian blue precipitate.

Halogen Percentage by Carius Method

M A
%X=Atomic Mass of XMolar Mass of AgX×Mass of AgX formedMass of Organic Compound×100%\% X = \frac{\text{Atomic Mass of } X}{\text{Molar Mass of } \text{Ag}X} \times \frac{\text{Mass of } \text{Ag}X \text{ formed}}{\text{Mass of Organic Compound}} \times 100\%
Parameters & Definitions

XX is halogen (Cl, Br, I), AgX\text{Ag}X is silver halide precipitate, and masses are measured in grams.

Quantitative formula for the estimation of halogens in organic compounds using the Carius method.