Explain,giving chemical equations,any two uses of chemical decomposition reactions in industry.

(N/A) $(i)$ In the manufacturing of cement,quicklime $(CaO)$ is used,which is obtained by the thermal decomposition of limestone $(CaCO_3)$:
$CaCO_3(s) \xrightarrow{\text{Heat}} CaO(s) + CO_2(g)$
$(ii)$ In the manufacturing of photochromic glass,silver chloride $(AgCl)$ or silver bromide $(AgBr)$ is used,which undergoes photochemical decomposition in sunlight to form metallic silver,causing the glass to darken:
$2AgCl(s) \xrightarrow{\text{Sunlight}} 2Ag(s) + Cl_2(g)$
$2AgBr(s) \xrightarrow{\text{Sunlight}} 2Ag(s) + Br_2(g)$