The Henderson Equation We cannot solve analytically so we make 2 simplifying assumptions concentration of each ion varies linearly from region I to region 2(1) a=Ci i.e,Yi= 1 for each ion(2) Then we obtain the Henderson equation ∑2u(c(2)-c() RT E h<|2LC;(2) ∑zll:2.co)]∑ ZiluThe Henderson Equation We cannot solve analytically so we make 2 simplifying assumptions: concentration of each ion varies linearly from region 1 to region 2 (1) i = ci , i.e.,  i  1 for each ion (2) Then we obtain the Henderson equation: ( )       = = = = − − = n i i i i n i i i i n i i i i i n i i i i i i J z u c z u c z u c c c c z z u E F RT 1 1 1 1 (1) (2) ln (2) (1) (2) (1)