(2)压强不变 Qn=C△T=2×R△T=400J 400 T=T,+ 280K ZR 459(1) 7 (3)体积不变 Q1=Cr△T=2×RAr=400 400 283K 5R P =1.04(m)8 （3）体积不变 （2）压强不变 Q C T R T J p p 400 2 7 =  = 2  = K R T T 280 7 400  2 = 1 + = 45.9( ) 1 1 2 2 l T VT V = = Q C T R T J V V 400 2 5 =  = 2  = K R T T 283 5 400  2 = 1 + = 1.04( ) 1 1 2 2 atm T PT P = =