question_answer

  Write about different chemical processes used for obtaining a metal from its oxides, for metals low in the reactivity series, metals in the middle of reactivity series and metals towards the top of the reactivity series.

Answer:

                  (i) For obtaining the metals that are low in the reactivity series, oxides of such metals can be reduced to metals by simply heating them in the air. For example, HgS or cinnabar is the ore of mercury metal which on heating changes to HgO. This metal oxide (HgO) gets reduced to mercury metal (Hg) on further heating. (ii) For obtaining metals that are in the middle of reactivity series, oxides of such metals can be reduced with coke (carbon) which acts as a reducing agent. For example, iron (III) oxide can be reduced to iron, as follows:  (iii) For obtaining metals that are high up in the reactivity series, their oxides are reduced to metals by electrolysis. For example, At cathode: At anode: