What characterizes an isobaric process?

An isobaric process is specifically characterized by a constant pressure throughout the entire process. This means that as a substance undergoes a change in state, such as heating or cooling, the pressure it experiences does not change. In an isobaric process, there may be changes in volume and temperature, but the defining feature is that the pressure remains steady.

For instance, when heating a gas in a piston-cylinder setup at constant pressure, the gas will expand, causing an increase in volume and often in temperature as energy is added. The work done by the system during this process can be calculated using the constant pressure and the change in volume. Therefore, the most accurate description of an isobaric process is that the pressure remains constant.