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 with dazzling brilliance in air to give MgO and `Mg_3 N_2`
`2Mg+O_2 to 2MgO`
`3Mg+ N_2 to Mg_3N_2`
ii) Quick lime heated with silica to form calcium silicate
`CaO+ SiO_2 to CaSio_3`
iii) Slaked lime reacts with chlorine gas to form bleaching powder
`2Ca(OH)_2+2Cl_2 to CaCl_2 +underset("Bleaching powder") underset(underbrace)Ca(OCl)_2+2H_2O`
iv) calcium nitrate on strong heating to form respective oxide
`2Ca(NO_3)_2 to 2CaO+4NO_2+O_2`