Derive the cation transport number by moving boundary method in the liquid electrolyte. In a tube$($radilis $2\mathrm{.}0mm)$ containing $0\mathrm{.}02MKCl,$ when an current of $18\mathrm{.}2mA$ is passed for $10$min, the boundary advanced $192mm.$ What is the transport number of $K^{+}$ion $?(15$ points$)$