W=-B△ volume work 高等化学教学资源库 ⊙-①-⊙-⊙-⊙ e.g.:for a constant P process W=-Fx×l Pex =-Pex·Al =-px(V2-V) =-Pex·AVpex V1 l W = −F l ex = − p  Al ex ( ) = − pex V2 −V1 = −pex V volume work e.g.: for a constant P process