question_answer

           Write balanced chemical equation for the reaction taking place when (a) Zinc carbonate is calcinated. (b) Zinc sulphide is roasted. (c) Zinc oxide is reduced in the zinc. (d) Cinnabar is heated in the air. (e) Manganese dioxide is heated with aluminium powder.

Answer:

                  (a) On calcination zinc carbonate decomposes to form its oxide.                (1) (b) On roasting zinc sulphide changes to its oxide. (1) (c) Zinc oxide is reduced in zinc.       (1) (d) Cinnabar (HgS) is heated in air to form metal mercury.                       (1) (e) Manganese dioxide on heating with aluminium powder will form manganese metal. Heat                                             (1)