question_answer

  Describe the underlying principle of the following metal refining methods : (a) Electrolyte refining                                                                                                                                                   (b) Vapor phase refining.                                                                                                                                                            

Answer:

                                                                                                (a) Electrolytic refining: This method is used for refining of metals and based upon the phenomenon of electrolysis.                                                                                                                                                                        1 Copper is refined using an electrolytic method. The reaction occurring at electrodes, are: e.g., At anode: At cathode:                                                                                                                            (b) Vapour phase refining: This method is based on the fact that certain metals are converted to their volatile compounds while the impurities are not affected during compound formation. The compound decomposes on heating to give pure metal.                                                                                                                                                         1 e.g.. Nickel is refined by vapour phase refining.