Thermodynamics Laws

Thermodynamics

Laws of Thermodynamics

• Zeroth Law of Thermodynamics: If two systems are in thermal equilibrium with a third system, then they are also in thermal equilibrium with each other.
• First Law of Thermodynamics: Energy cannot be created or destroyed, only converted from one form to another. ΔE = Q - W, where ΔE is the change in energy, Q is the heat added, and W is the work done.
• Second Law of Thermodynamics: The total entropy of a closed system always increases over time, except in reversible processes. ΔS = ΔQ / T, where ΔS is the change in entropy, ΔQ is the heat added, and T is the temperature.
• Third Law of Thermodynamics: As the temperature of a system approaches absolute zero, the entropy of the system approaches a minimum value.

Thermodynamic Systems

• Isolated System: A system that does not exchange matter or energy with its surroundings.
• Closed System: A system that does not exchange matter with its surroundings, but can exchange energy.
• Open System: A system that can exchange both matter and energy with its surroundings.

Thermodynamic Properties

• Internal Energy (U): The total energy of a system, including kinetic energy, potential energy, and potential energy associated with the interactions between particles.
• Enthalpy (H): A measure of the total energy of a system, including internal energy and the energy associated with the pressure and volume of a system. H = U + PV, where P is the pressure and V is the volume.
• Entropy (S): A measure of the disorder or randomness of a system.
• Free Energy (G): A measure of the energy available to do work in a system. G = H - TS, where T is the temperature and S is the entropy.

Thermodynamic Processes

• Isothermal Process: A process that occurs at a constant temperature.
• Adiabatic Process: A process that occurs without the transfer of heat.
• Isobaric Process: A process that occurs at a constant pressure.
• Isochoric Process: A process that occurs at a constant volume.

Laws of Thermodynamics

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

Thermodynamic Systems

• An isolated system does not exchange matter or energy with its surroundings.
• A closed system does not exchange matter with its surroundings, but can exchange energy.
• An open system can exchange both matter and energy with its surroundings.

Thermodynamic Properties

• Internal Energy (U) is the total energy of a system, including kinetic energy, potential energy, and potential energy associated with interactions between particles.
• Enthalpy (H) is a measure of the total energy of a system, including internal energy and the energy associated with pressure and volume, H = U + PV.
• Entropy (S) is a measure of the disorder or randomness of a system.
• Free Energy (G) is a measure of the energy available to do work in a system, G = H - TS.

Thermodynamic Processes

• Isothermal Process: a process that occurs at a constant temperature.
• Adiabatic Process: a process that occurs without the transfer of heat.
• Isobaric Process: a process that occurs at a constant pressure.
• Isochoric Process: a process that occurs at a constant volume.