the equation derived from 2a is ficks second law

b) The use of a capillary tube allows the diffusion path to be considered as one- dimensional. Using a one-dimensional view of Fick's first law (1), and the equation derived above in 2 a), show how equation (2) is obtained. The relationship between concentration and conductivity should be modelled using equation (3). ac J = -D (1) D Ak XV At CsAc (2) k C2 = Cs (3)