Discuss the Hittorf method of determination of transport number
The essential feature of the Hittorf`s method as applied to electrode solution is that the ionic flow through the homogeneous zone is measured simultaneously with the electric current. In binary systems where we have only one kind of counterion the membrane can be considered to be homogeneous and thus the Hittorf`s method is applicable. Strictly speaking this is true only for the ideal membrane where the transport number of the counterion is equal to one. Therefore this transport number actually measures the ideality of the ion exchange membrane.