Final answer:
The pressure-volume work in a reaction with a net mole increase of gases is negative.
Step-by-step explanation:
The pressure-volume work in a reaction with a net mole increase of gases is negative. When the volume of a system increases at a constant pressure, the system loses energy by performing work on its surroundings. Therefore, the work done by the system is negative, indicating a loss of energy. On the other hand, if the volume decreases, the work done by the system is positive, indicating an increase in energy.