1.
Introduction to Chemistry
Chemistry is the scientific study of matter—its properties, composition, structure,
and the changes it undergoes. It plays a central role in science and technology and
connects physics, biology, environmental science, and materials science.
Chemistry is often called the central science because it bridges other natural
sciences. It is foundational for innovations in health, agriculture, industry,
energy, and the environment.
2. Branches of Chemistry
1. Organic Chemistry
Deals with carbon-containing compounds. It includes hydrocarbons and their
derivatives, essential in pharmaceuticals, petrochemicals, dyes, and polymers.
2. Inorganic Chemistry
Studies minerals, metals, and non-metals. It explores periodic table trends,
coordination compounds, and inorganic reaction mechanisms.
3. Physical Chemistry
Connects chemical phenomena to physical principles—thermodynamics, quantum
chemistry, kinetics, and spectroscopy.
4. Analytical Chemistry
Focuses on identifying substances (qualitative analysis) and determining how much
is present (quantitative analysis). Techniques include titration, chromatography,
and spectroscopy.
5. Biochemistry
Studies chemical processes in living organisms, including DNA replication, enzyme
functions, and metabolism.
6. Environmental Chemistry
Explores chemical changes in the environment, pollutants, and green chemistry for
sustainable practices.
3. Atomic Structure
Dalton’s Atomic Theory: Atoms are indivisible, all atoms of an element are
identical.
Modern Atomic Theory: Incorporates subatomic particles—protons, neutrons,
electrons.
Bohr’s Model: Electrons revolve in discrete orbits with quantized energy.
Quantum Mechanical Model: Electrons as wave-particles described by Schrödinger's
equation.
Orbitals & Quantum Numbers: n (principal), l (azimuthal), m (magnetic), s (spin).
Aufbau Principle, Pauli Exclusion Principle, and Hund’s Rule govern electron
configurations.
4. Chemical Bonding
Ionic Bonding: Transfer of electrons, forming cations and anions (e.g., NaCl).
Covalent Bonding: Sharing of electron pairs (e.g., H₂O, CH₄).
Coordinate Bonding: Shared electrons provided by one atom.
Metallic Bonding: Electrons delocalized over metal atoms.
Intermolecular Forces: Van der Waals forces, hydrogen bonding, dipole-dipole.
VSEPR Theory, Hybridization, and Molecular Orbital Theory explain molecular shapes
and bonding.
5. States of Matter
Solids: Fixed shape and volume, strong intermolecular forces.
Liquids: Fixed volume, take the shape of container.
Gases: No fixed volume or shape, highly compressible.
Gas Laws:
Boyle’s Law: P ∝ 1/V
Charles’s Law: V ∝ T
Avogadro’s Law: V ∝ n
Ideal Gas Equation: PV = nRT
Kinetic Molecular Theory explains gas behavior at microscopic level.
6. Thermodynamics
System and Surroundings
Laws of Thermodynamics:
Zeroth Law: Thermal equilibrium.
First Law: Energy conservation (ΔU = q - w).
Second Law: Entropy always increases.
Third Law: Entropy of a perfect crystal at 0 K is zero.
Key Terms: Enthalpy (ΔH), Entropy (ΔS), Gibbs Free Energy (ΔG), Heat capacity,
Internal energy.
7. Chemical Equilibrium
Reversible reactions reach dynamic equilibrium.
Law of Mass Action: Equilibrium constant K = [products]/[reactants]
Le Chatelier’s Principle: System responds to oppose change.
Factors Affecting Equilibrium: Temperature, pressure, concentration.
8. Chemical Kinetics
Rate of Reaction: Change in concentration over time.
Rate Laws: Rate = k[A]^m[B]^n
Order and Molecularity
Arrhenius Equation: k = Ae^(-Ea/RT)
Activation Energy and Catalysts
9. Acids, Bases, and Salts
Arrhenius Theory, Bronsted-Lowry Theory, Lewis Theory
pH and pOH: pH = -log[H+]
Buffer Solutions
Titrations: Strong acid vs base, indicators, end point.
10. Electrochemistry
Redox Reactions: Oxidation (loss), Reduction (gain) of electrons.
Electrochemical Cells: Galvanic (voltaic) and electrolytic cells.
Standard Electrode Potential (E°)
Nernst Equation for calculating electrode potential.
Batteries, Fuel Cells, Corrosion
11. Coordination Compounds
Ligands: Molecules or ions that donate lone pair to central atom.
Coordination Number
Nomenclature of complexes.
Isomerism: Structural and stereoisomerism.
Valence Bond Theory, Crystal Field Theory
