9.5 Thermodynamic Processes

PV Diagrams

PV Diagrams are graphs which have pressure on the y-axis and volume on the x-axis. PV Diagrams are essential in modeling a thermodynamic process. A gas can start at any point in the graph, as it can have any pressure or volume. Then, a thermodynamic process will move the gas to a new point in the graph. The gas may take any path on the graph to reach that point. When the gas takes the path between the 2 points, the area bounded by the graph will show the work done onto the gas. From the equation ${W=-P \Delta V}$, we can see that if the gas decreases in volume the work is positive, and if the gas increases in volume the work will be negative.