Chemistry Formula Sheet for CUET UG 2025

📋 Comprehensive Collection of Essential Chemistry Formulas

This formula sheet covers all essential topics for CUET UG Chemistry. Keep this handy for quick revision and last-minute preparation.

⚗️ Physical Chemistry

Atomic Structure

• Bohr’s Model: E_n = -2.18 × 10⁻¹⁸ J/n²
• de Broglie Equation: λ = h/(mv)
• Heisenberg Uncertainty: Δx × Δp ≥ h/(4π)
• Rydberg Formula: 1/λ = R_H(1/n₁² - 1/n₂²)
• Ionization Energy: IE = 2.18 × 10⁻¹⁸ J/n²

Chemical Bonding

• Bond Order: BO = (N_b - N_a)/2
• Dipole Moment: μ = q × d
• Lattice Energy: U = k(Q₁Q₂)/r₀
• Born-Haber Cycle: ΔH_f = ΔH_sub + IE + EA + U + ΔH_f(atom)
• Hybridization: sp = 2 (linear), sp² = 3 (trigonal), sp³ = 4 (tetrahedral)

States of Matter

• Ideal Gas Law: PV = nRT
• Dalton’s Law: P_total = P₁ + P₂ + P₃ + …
• Graham’s Law: r₁/r₂ = √(M₂/M₁)
• Van der Waals Equation: (P + an²/V²)(V - nb) = nRT
• Charles’s Law: V₁/T₁ = V₂/T₂
• Boyle’s Law: P₁V₁ = P₂V₂
• Avogadro’s Law: V/n = constant

Solutions

• Molarity: M = moles of solute/volume of solution (L)
• Molality: m = moles of solute/mass of solvent (kg)
• Mole Fraction: X_A = moles of A/total moles
• Mass Percent: % = (mass of solute/mass of solution) × 100
• Normality: N = equivalents of solute/volume of solution (L)
• Dilution: M₁V₁ = M₂V₂
• Raoult’s Law: P = X_A × P_A⁰
• Elevation of Boiling Point: ΔT_b = K_b × m
• Depression of Freezing Point: ΔT_f = K_f × m
• Osmotic Pressure: π = iMRT

Chemical Thermodynamics

• First Law: ΔU = q + w
• Work Done: w = -PΔV (at constant pressure)
• Enthalpy Change: ΔH = ΔU + PΔV
• Gibbs Free Energy: ΔG = ΔH - TΔS
• Standard Free Energy: ΔG° = -RT ln K
• Equilibrium Constant: K = e^(-ΔG°/RT)
• Hess’s Law: ΔH_total = ΔH₁ + ΔH₂ + ΔH₃
• Entropy Change: ΔS = q_rev/T
• Heat Capacity: C = q/ΔT

Chemical Kinetics

• Rate Law: Rate = k[A]^m[B]^n
• Rate Constant: k = Rate/[A]^m[B]^n
• Half Life (First Order): t_½ = 0.693/k
• Arrhenius Equation: k = Ae^(-Ea/RT)
• Activation Energy: E_a = -R × (slope of ln k vs 1/T)
• Integrated Rate Laws:
  • Zero Order: [A] = [A]₀ - kt
  • First Order: ln[A] = ln[A]₀ - kt
  • Second Order: 1/[A] = 1/[A]₀ + kt

Chemical Equilibrium

• Equilibrium Constant: K_c = [C]^c[D]^d/[A]^a[B]^b
• Equilibrium Constant (Pressure): K_p = (P_C)^c(P_D)^d/(P_A)^a(P_B)^b
• Relationship: K_p = K_c(RT)^(Δn)
• Reaction Quotient: Q = [C]^c[D]^d/[A]^a[B]^b
• ICE Table: Initial, Change, Equilibrium
• Le Chatelier’s Principle: System opposes change

Electrochemistry

• Faraday’s Laws: m = ZQ, where Q = It
• Nernst Equation: E = E° - (RT/nF)ln Q
• Standard Electrode Potential: E°cell = E°cathode - E°anode
• Gibbs Free Energy: ΔG = -nFE
• Electrical Work: w = -nFE
• Conductivity: κ = 1/R × l/A
• Molar Conductivity: Λ_m = κ/c
• Kohlrausch’s Law: Λ_m⁰ = λ⁺ + λ⁻
• pH Calculation: pH = -log[H⁺]
• Henderson-Hasselbalch: pH = pKa + log([A⁻]/[HA])

🧪 Organic Chemistry

Basic Concepts

• Molecular Formula: Actual number of atoms
• Empirical Formula: Simplest whole number ratio
• Structural Formula: Shows bonding arrangement
• Degree of Unsaturation: DU = (2C + 2 + N - H - X)/2

Hydrocarbons

• Alkanes: C_nH_2n+2 (saturated)
• Alkenes: C_nH_2n (one double bond)
• Alkynes: C_nH_2n-2 (one triple bond)
• Aromatic: C_nH_2n-6 (benzene ring)

Functional Groups

• Alcohol: -OH
• Aldehyde: -CHO
• Ketone: >C=O
• Carboxylic Acid: -COOH
• Ester: -COOR
• Amine: -NH₂
• Amide: -CONH₂
• Ether: -O-

IUPAC Nomenclature

• Find longest carbon chain (parent)
• Number from end giving lowest numbers to substituents
• Name substituents alphabetically
• Use prefixes: di-, tri-, tetra- for multiple substituents

Isomerism

• Structural Isomers: Different connectivity
• Stereoisomers: Same connectivity, different arrangement
• Geometric Isomers: cis-trans (E/Z) notation
• Optical Isomers: chiral centers, R/S notation

Organic Reactions

• Substitution: SN1 (carbocation), SN2 (backside attack)
• Elimination: E1 (carbocation), E2 (concerted)
• Addition: A + B → AB
• Oxidation: Increase in oxidation number
• Reduction: Decrease in oxidation number

Reaction Mechanisms

• SN1 Rate: Rate = k[substrate]
• SN2 Rate: Rate = k[substrate][nucleophile]
• E1 Rate: Rate = k[substrate]
• E2 Rate: Rate = k[substrate][base]

Important Reactions

• Aldol Condensation: Two aldehydes/ketones + base → β-hydroxy carbonyl
• Cannizzaro Reaction: Disproportionation of aldehydes in strong base
• Hofmann Rearrangement: Amide → amine (one carbon less)
• Wurtz Reaction: 2R-X + 2Na → R-R + 2NaX
• Grignard Reaction: R-MgX + carbonyl → alcohol

Polymers

• Addition Polymers: Polyethylene, Polystyrene
• Condensation Polymers: Nylon, Polyester
• Natural Polymers: Cellulose, Proteins, DNA

Biomolecules

• Carbohydrates: C_n(H₂O)_m (sugars, starch, cellulose)
• Proteins: Amino acids linked by peptide bonds
• Lipids: Fats and oils
• Nucleic Acids: DNA, RNA

🏭 Inorganic Chemistry

Periodic Properties

• Atomic Radius: Increases down group, decreases across period
• Ionization Energy: Decreases down group, increases across period
• Electron Affinity: Generally increases across period
• Electronegativity: Increases across period, decreases down group
• Metallic Character: Increases down group, decreases across period

Classification of Elements

• s-block: Groups 1, 2 (alkali, alkaline earth metals)
• p-block: Groups 13-18
• d-block: Transition metals (Groups 3-12)
• f-block: Lanthanides and actinides

Chemical Bonding

• Ionic Bond: Electrostatic attraction between ions
• Covalent Bond: Sharing of electron pairs
• Metallic Bond: Delocalized electrons in metal lattice
• Hydrogen Bond: H attached to electronegative atom

Coordination Compounds

• Coordination Number: Number of ligands attached to central metal
• Oxidation State: Charge on central metal ion
• Ligand: Molecule/ion donating electron pair
• Chelate: Multidentate ligand forming ring structures
• Crystal Field Theory: Splitting of d-orbitals in ligand field
• Stability Constant: Kf = [ML_n]/[M][L]^n

Acid-Base Chemistry

• Arrhenius: Acid produces H⁺, Base produces OH⁻
• Bronsted-Lowry: Acid donates H⁺, Base accepts H⁺
• Lewis: Acid accepts electron pair, Base donates electron pair
• pH Scale: 0-14 (acidic 0-6, neutral 7, basic 8-14)
• Buffer Solution: Resists pH changes

Redox Reactions

• Oxidation: Loss of electrons (increase in oxidation number)
• Reduction: Gain of electrons (decrease in oxidation number)
• Oxidizing Agent: Gets reduced (accepts electrons)
• Reducing Agent: Gets oxidized (donates electrons)
• Balancing Redox: Half-reaction method

Hydrogen and Its Compounds

• Water: H₂O (universal solvent)
• Hydrogen Peroxide: H₂O₂ (oxidizing agent)
• Hydrogen Sulfide: H₂S (weak acid)
• Ammonia: NH₃ (weak base, ligand)

s-Block Elements

• Group 1 (Alkali Metals): Li, Na, K, Rb, Cs, Fr
• Group 2 (Alkaline Earth Metals): Be, Mg, Ca, Sr, Ba, Ra
• General Properties: Soft, low density, highly reactive

p-Block Elements

• Group 13: B, Al, Ga, In, Tl
• Group 14: C, Si, Ge, Sn, Pb
• Group 15: N, P, As, Sb, Bi
• Group 16: O, S, Se, Te, Po
• Group 17: F, Cl, Br, I, At (halogens)
• Group 18: He, Ne, Ar, Kr, Xe, Rn (noble gases)

d-Block Elements (Transition Metals)

• General Properties: High melting/boiling points, colored compounds, catalytic activity
• Variable Oxidation States: Multiple oxidation numbers possible
• Complex Formation: Form colored complexes
• Magnetic Properties: Many are paramagnetic

f-Block Elements

• Lanthanides: 57-71 (Ce to Lu)
• Actinides: 89-103 (Th to Lr)
• General Properties: Radioactive (actinides), similar chemical properties

Environmental Chemistry

• Air Pollution: CO, CO₂, SO₂, NOₓ, CFCs
• Water Pollution: Heavy metals, organic pollutants
• Soil Pollution: Pesticides, industrial waste
• Green Chemistry: Sustainable chemical processes

📊 Quick Reference Tables

Atomic Weights (Approximate)

Common Ions

Standard Electrode Potentials

Thermodynamic Constants

Common Solvents

🎯 Exam Tips

Quick Revision Strategy

1. Memorize important constants - R, F, N_A
2. Master periodic trends - predict properties
3. Practice nomenclature - systematic naming
4. Understand reaction mechanisms - not just memorization
5. Review balancing equations - redox and complex reactions

Common Mistakes to Avoid

1. Incorrect oxidation state assignment
2. Wrong molecular geometry predictions
3. Improper equation balancing
4. Confusion between similar compounds
5. Incorrect application of laws/rules

Problem-Solving Approach

1. Identify the type of problem (stoichiometry, equilibrium, etc.)
2. Write down given information and what’s required
3. Select appropriate formula or concept
4. Show calculations clearly with units
5. Check answer for reasonableness

Memory Aids

1. Diagonal Relationships: Li-Mg, Be-Al, B-Si
2. Exception to Trends: Ionization energy of Group 2 and 15
3. Color Coding: Transition metal complexes
4. Reaction Patterns: Functional group transformations

🔗 Additional Resources

Practice Materials

• Chemistry Practice Questions
• Previous Year Questions
• Mock Tests

Study Support

• Expert Guidance
• Study Groups

📌 Remember: Understanding concepts is crucial for chemistry - formulas are tools, not just memorization items!

Last Updated: October 2024 | CUET UG 2025 Chemistry Formula Sheet