The Ion transference number is the ratio of the charge transferred by the ion to the total charge. If the charges transferred by the two ion migration numbers are q+ and q-, respectively, the total charge passed is: Q=q++q-, and the migration numbers of positive and negative ions are: t+=q+/Q and t-=q- /Q, t++t-=1. The ion migration number can be directly measured by the Hittoff method, the interface movement method and the electromotive force method.
