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.

Explanation

(i) Magnesium burns in air with dazzling white light.
`5Mg+underset(("in air"))ubrace(O_(2)+N_(2)) overset("heat")to2MgO+Mg_(1)N_(2)`
(ii) `CaO+SiO_(2) to underset("Calcium silicate")(CaSiO_(3))`
(iii) `Ca(OH)_(2) to Cl_(2) to underset("Bleaching powder")(CaOCl_(2)+H_(2)O)`
(iv) `2Ca(NO_(3))_(2) to 2CaO+4NO_(2)+O_(2)`