thermodynamic identity

The thermodynamic identity describes how changes in a system's energy relate to work done and heat exchanged. It states that the change in a system's internal energy equals the heat added to it minus the work the system does on its surroundings. Mathematically, it's expressed as dU = dQ - dW. This principle helps us understand energy flows in processes like engines and refrigerators, ensuring energy conservation. Essentially, it links energy transfer as heat and work to the total energy within a system, allowing precise analysis of thermodynamic processes.