Arrhenius in 1887 put forward the theory of electrolytic dissociation in aqueous solution. The main points of this theory are:
(1) The electrolytes in aqueous solution form charged particles called ions. The positively charged particles are called cations and the negatively charged particles are called anions.
(2) There is present a dynamic equilibrium between the undissociated molecules and the dissociated ions of the electrolyte in aqueous solution.
(3) The ions move freely under the influence of an applied electric field. Cations move towards the negative electrode or cathode and the anions move towards the positive electrode or anode.
(4) The number of cations and anions in the solution of an electrolyte may be different. However, the total charge carried by cations is equal to the total charge carried by the anions. The solution as a whole is electrically neutral.
(5) The extent of dissociation is different for different electrolytes and depends on