A similar treatment to that used for reactivity ratios can be used to obtain an equation to describe multi-component systems in terms of Q and e values.
d[Mi] = [Mi f Q? e"61′ + [Mi] [M2] Q1 Q2 e"6162 +……… [Mi] [Mn] Q1 Qn e"61®"
d [Mz] [M2 f Q§ e** + [M2] [Mi] Q2 Q1 e-®1®2 +……… [M2] [Mn] Q2 Qn o-®2®"
d[Mi] = [Mi f Q? e"®1" + [Mi] [M2] Q1 Q2 o-®1®2 +…….. [Mi] [Mn] Q1 Qn o-616"
d [Mn] [Mn f Qn e-®"2 + [Mi] [Mn] Q1 Qn e-01®" +…………….. [Mn] [Mn-i] Qn Qn-1 e’®"®-1