In an isobaric process, what remains constant?

In an isobaric process, the defining characteristic is that the pressure remains constant throughout the process. This means that regardless of changes that may occur in temperature or volume during the process, the pressure does not change.

In such processes, when a system undergoes a change (like heating a gas), it may expand or contract, which can lead to changes in volume and potentially temperature. However, the pressure, defined as the force per unit area exerted by the gas, remains fixed.

For example, if a gas is heated at constant pressure, it will expand, increasing its volume and, depending on the amount of heat added, possibly its temperature as well. The heat added in this case can be directly related to changes in the internal energy and work done on/by the system, but the pressure as a variable does not change.

Understanding this thermodynamic principle is essential for analyzing processes where pressure plays a critical role, such as in engines or refrigerators. The constancy of pressure helps simplify calculations and predictions about the behavior of the system involved.