Write balanced equations for each of the following reactions.
(a) When mercury(II) oxide is heated, it decomposes to form O2 and mercury metal.
(b) When copper(II) nitrate is heated strongly, it decomposes to form copper(II) oxide, nitrogen dioxide, and oxygen.
(c) Lead(II) sulfide, PbS(s), reacts with ozone to form PbSO4(s) and O2(g).
(d) When heated in air, ZnS(s) is converted to ZnO.
(e) Potassium peroxide reacts with CO2(g) to give potassium carbonate and O2.
(f) Oxygen is converted to ozone in the upper atmosphere.