Physical Chemistry Short Notes [PDF] 📚

Physical Chemistry Short Notes

Physical chemistry is a branch of chemistry that deals with the physical properties of matter and the principles that govern chemical reactions. Here are some key concepts and formulas:

Thermodynamics

• System: A part of the universe under study.
• Surroundings: The rest of the universe.
• Internal energy (U): The total energy of a system.
• Enthalpy (H): Heat absorbed or released at constant pressure.
• Entropy (S): A measure of disorder.
• Gibbs free energy (G): A measure of spontaneity of a process.
• First law of thermodynamics: Energy cannot be created or destroyed, only transferred.
• Second law of thermodynamics: The entropy of the universe always increases.
• Third law of thermodynamics: The entropy of a perfect crystal at absolute zero is zero.

Formulas:

• ΔU = q + w
• ΔH = ΔU + PΔV
• ΔS = qrev/T
• ΔG = ΔH - TΔS

Kinetics

• Rate of reaction: The change in concentration of a reactant or product per unit time.
• Rate constant (k): A proportionality constant that relates the rate of a reaction to the concentrations of reactants.
• Order of reaction: The power to which the concentration of a reactant is raised in the rate law.
• Half-life: The time required for the concentration of a reactant to decrease by half.
• Arrhenius equation: k = Ae^(-Ea/RT)

Quantum Mechanics

• Wave-particle duality: Matter can exhibit both wave-like and particle-like properties.
• Schrödinger equation: An equation that describes the wave function of a particle.
• Quantum numbers: n, l, m, and s, which describe the energy, shape, orientation, and spin of an electron.
• Atomic orbitals: Regions of space where an electron is most likely to be found.
• Molecular orbital theory: A theory that describes the bonding between atoms in molecules.

Electrochemistry

• Electrolysis: The process of using electricity to drive a non-spontaneous chemical reaction.
• Electrolytic cell: A cell in which electrolysis occurs.
• Galvanic cell: A cell that generates electricity from a spontaneous chemical reaction.
• Standard reduction potential: The potential of a half-reaction under standard conditions.
• Nernst equation: Ecell = E°cell - (RT/nF)lnQ

Note: This is just a brief overview of physical chemistry. For a more in-depth understanding, it is recommended to consult textbooks or online resources.