(a) Name the residue obtained on strongly heating the following:
(i) ZnCO(_3) in an open crucible;
(ii) CuSO(_4), 5H(_2)O and then allowing it to cool in a desiccator.
(b) State the colour changes observed on heating and cooling in each case in(a) above.
Explanation
(a) (i) Yellow zinc (II) oxide is the residue when Zinc (II) trioxocarbonate (IV) is strongly heated in an open crucible.
(ii) White powdery mass of anhydrous copper(II) tetraoxosulphate (VI) is left as the residue in the desiccator
(b)(a)(i) above when hot, it is yellow and white when cold.
(ii) above, when hot, it is white and blue when cold