Va +VB △SA=n4RLn Va VA+VB A SB=neRLn VB AS=△SA+ASB =-an,a Va =-nARLnyA-nERLnyB >0 y为摩尔分数 33 ΔS A = nA RLn A A B V V +V ΔSB = nB RLn B A B V V +V ΔS=ΔS A +ΔSB = - nA RLn A B A V V V + - nB RLn A B B V V V + = - nA RLnyA- nB RLnyB > 0 y 为摩尔分数