The First Law of Thermodynamics, also known as the law of conservation of energy, states that the total amount of energy in a closed system remains constant, regardless of the changes that occur within the system.

The Second Law of Thermodynamics states that heat always flows spontaneously from hotter objects to colder objects, leading to an increase in entropy and a decrease in the system's ability to do useful work.

The Third Law of Thermodynamics states that the entropy of a perfect crystal at absolute zero is zero. This means that all the molecules in the crystal are in their lowest energy state and there is no disorder.

The Second Law of Thermodynamics introduces the concept of entropy, which measures the degree of disorder or randomness in a system. It states that the total entropy of an isolated system always increases over time.

The First Law of Thermodynamics is mathematically expressed as dU = Q - W, where dU represents the change in internal energy, Q represents the heat transferred into the system, and W represents the work done by the system.

An isothermal process is a thermodynamic process in which the temperature of the system remains constant while heat is absorbed and work is done.

The ideal gas law, PV = nRT, relates the pressure (P), volume (V), temperature (T), and number of moles (n) of an ideal gas. R is the ideal gas constant.

An adiabatic process is a thermodynamic process in which there is no heat transfer between the system and its surroundings.

The efficiency of a heat engine is calculated as the ratio of the work output to the heat input.

An isochoric process is a thermodynamic process in which the volume of the system remains constant.

The Carnot cycle is a hypothetical heat engine cycle that operates between two reservoirs at different temperatures and achieves the maximum possible efficiency.

In a reversible process, the change in entropy (dS) is equal to the heat transferred (dQ) divided by the absolute temperature (T).

The triple point of a substance is the temperature and pressure at which the solid, liquid, and gas phases coexist in equilibrium.

The Clausius statement of the Second Law of Thermodynamics states that heat cannot flow spontaneously from a colder to a hotter body.

The Kelvin statement of the Second Law of Thermodynamics states that it is impossible to construct a heat engine that operates with 100% efficiency.