Laws of Thermodynamics

Thermodynamics

Laws of Thermodynamics

• Zeroth Law: If two systems are in thermal equilibrium with a third system, then they are also in thermal equilibrium with each other.
• First Law: Energy cannot be created or destroyed, only converted from one form to another. (ΔE = Q - W)
• Second Law: The total entropy of an isolated system always increases over time, except in reversible processes.
• Third Law: As the temperature of a system approaches absolute zero, its entropy approaches a minimum value.

Thermodynamic Systems

• Isolated System: No energy or matter can be exchanged with the surroundings.
• Closed System: Energy can be exchanged, but not matter.
• Open System: Both energy and matter can be exchanged.

Thermodynamic Properties

• Internal Energy (U): Total energy of a system.
• Entropy (S): Measure of disorder or randomness.
• Enthalpy (H): Total heat content of a system.
• Free Energy (G): Energy available to do work.

Thermodynamic Processes

• Isothermal Process: Constant temperature.
• Adiabatic Process: No heat is transferred.
• Isobaric Process: Constant pressure.
• Isochoric Process: Constant volume.

Thermodynamic Cycles

• Carnot Cycle: Ideal heat engine with maximum efficiency.
• Refrigeration Cycle: Removes heat from a system, transferring it to a heat sink.

Laws of Thermodynamics

• The Zeroth Law of Thermodynamics states that if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other.
• The First Law of Thermodynamics states that energy cannot be created or destroyed, only converted from one form to another, and is mathematically represented as ΔE = Q - W.
• The Second Law of Thermodynamics states that the total entropy of an isolated system always increases over time, except in reversible processes.
• The Third Law of Thermodynamics states that as the temperature of a system approaches absolute zero, its entropy approaches a minimum value.

Thermodynamic Systems

• An isolated system is a system where no energy or matter can be exchanged with the surroundings.
• A closed system is a system where energy can be exchanged, but not matter.
• An open system is a system where both energy and matter can be exchanged.

Thermodynamic Properties

• Internal Energy (U) is the total energy of a system.
• Entropy (S) is a measure of disorder or randomness in a system.
• Enthalpy (H) is the total heat content of a system.
• Free Energy (G) is the energy available to do work in a system.

Thermodynamic Processes

• An isothermal process is a process that occurs at a constant temperature.
• An adiabatic process is a process in which no heat is transferred.
• An isobaric process is a process that occurs at a constant pressure.
• An isochoric process is a process that occurs at a constant volume.

Thermodynamic Cycles

• A Carnot Cycle is an ideal heat engine with maximum efficiency.
• A Refrigeration Cycle is a cycle that removes heat from a system and transfers it to a heat sink.