In an insulated container 1 mol of a liquid, molar volume 100 mL is kept at 1 bar. Liquid is steeply taken to 100 bar, when volume of liquid decreases by 1 mL. Find ∆H and ∆U for the process.

Volume of 1 mol of liquid = 100 mL at pressure 1 bar volume of 1 mole liquid = 99 mL at pressure 100 bar The process is irreversible as it is steeply changed from 1 bar to 100 bar. Therefore,W=−PV2−V1=−100(99−100)=100barmL Also ΔU=q+Wq=0 since container is insulated ∴ΔU=100barmL Also ΔH=ΔU+PΔV=ΔU+P2V2−P1V1 =100+(100×99−1×100)=9900 bar mL.