解:(1)等温过程气体对外作功为 w=rao pdv s rav rt dv=RTIn3 =8.31×298×1.0986=272×103J (2)绝热过程气体对外作功 W=avo PdV= pky 3V0 (37-1 y 1-31y 1-y200= y-1 220×103J解:(1)等温过程气体对外作功为 = 0 0 3V W V PdV = 0 0 3V W V PdV = 8.312981.0986 (2)绝热过程气体对外作功 2 20 10 J 3 = . 0 0 1 1 3 1 PV γ γ − − = − = = RT ln3 0 0 3V V dV V RT − = 0 0 3 0 0 V V γ PV V dV 2.72 10 J 3 = RT γ γ 1 1 3 1 − − = − 0 0 1 0 1 1 (3 1) PV γ V γ − − = − −