Write balanced chemical equations for the following:
$(i)$ Bleaching powder is kept open in air.
$(ii)$ Blue crystals of copper sulphate are heated.
$(iii)$ Chlorine gas is passed through dry slaked lime.

(N/A) $(i) \text{ } CaOCl_2(s) + CO_2(g) \to CaCO_3(s) + Cl_2(g)$
$(ii) \text{ } CuSO_4 \cdot 5H_2O(s) \xrightarrow{\text{Heat}} CuSO_4(s) + 5H_2O(g)$
$(iii) \text{ } Ca(OH)_2(s) + Cl_2(g) \to CaOCl_2(s) + H_2O(l)$