Write balanced chemical equations for each of the following reactions, omitting (where relevant) all spectator species.
(a) Solid calcium dissolves in dilute perchloric acid (HClO4) giving a colourless conducting solution and hydrogen gas.
(b) Butanone (C4H8O) is burnt with oxygen producing carbon dioxide and water only.
(c) Zinc nitrate (Zn (NO3)2) is decomposed by heating, producing zinc oxide (ZnO), nitrogen dioxide and oxygen.