What happens when:
$(i)$ magnesium is burnt in air
$(ii)$ quick lime is heated with silica
$(iii)$ chlorine reacts with slaked lime
$(iv)$ calcium nitrate is heated?

(N/A) $(i)$ Magnesium burns in air with a dazzling light to form $MgO$ and $Mg_3N_2$.
$2Mg + O_2 \xrightarrow{\Delta} 2MgO$
$3Mg + N_2 \xrightarrow{\Delta} Mg_3N_2$
$(ii)$ Quick lime $(CaO)$ combines with silica $(SiO_2)$ to form calcium silicate (slag).
$CaO + SiO_2 \xrightarrow{\Delta} CaSiO_3$
$(iii)$ When chlorine reacts with slaked lime,it forms bleaching powder.
$Ca(OH)_2 + Cl_2 \xrightarrow{\Delta} CaOCl_2 + H_2O$
$(iv)$ Calcium nitrate,on heating,decomposes to give calcium oxide,nitrogen dioxide,and oxygen.
$2Ca(NO_3)_2(s) \xrightarrow{\Delta} 2CaO(s) + 4NO_2(g) + O_2(g)$