87.4 Activity and activity coefficient 1. Concepts For ideal or dilute non-electrolyte solution AB=uR(T)+RTIn m For nonideal solution of non-electrolytes uB=UR(T)+RtIn a Bm aB,m rBh e For electrolytic solution such as dilute Hcl solution HCI(aHci=h(au+)+cl(a) y+ a=y-6For ideal or dilute non-electrolyte solution B B B ( ) ln m T RT m   = + For nonideal solution of non-electrolytes B B B,m   = + ( ) ln T RT a B B,m B,m m a m =  1. Concepts For electrolytic solution such as dilute HCl solution: HCl H Cl HCl( ) H ( ) Cl ( ) a a a + − + − = + m a m  + + + = m a m  − − − = §7.4 Activity and activity coefficient