Question

It would also be possible to separate Co2+ and Ni2+ on a cation-exchange column as opposed to the anion-exchange resin used in this experiment. What is the main advantage of the procedure we used?

Answer 1

Solution:-

In this experiment, principles of ion-exchange will be used to separate cobalt and nickel ions (Co2+ and Ni2+) based on formation of anionic complexes with chloride. Many metal ions form anionic chloro-complexes in concentrated hydrochloric acid solutions. These chloro-complexes can be exchanged with mobile anions originally associated with the immobile cationic groups of an ion-exchange resin. The retention of the anionic chloro-complexes on the ion-exchange column depends on the nature of the complexes. Metal ions that do not form anionic chloro-complexes will be repelled by the cationic groups on the resin and will therefore elute from the column.