(a) The chemical name of bleaching powder is calcium oxychloride and its formula is Ca(ClO)2
(b) When exposed to air, bleaching powder reacts with carbon dioxide in air to produce calcium carbonate and chlorine. Thus, it smells of chlorine.
(c) When bleaching powder is treated with an excess of dilute hydrochloric acid, all the chlorine present in it is liberated. The following equation shows the reaction taking place.