Question

When happens when:

A Magnesium is burnt in air

B Quick lime is heated with silica

C Chlorine reacts with slaked lime

D Calcium nitrate is heated

Answer 1

$\text{Reaction of magnesium with air}\left(O_2\right):$

We know air is the combination of nitrogen and oxygen. Hence, magnesium burns in air with a dazzling light to form $MgO$ and $M{g}_3{N}_2$.
Involved reactions follow as:

$2Mg+O_2\stackrel{heat}{\to }2MgO$

$3Mg+N_2\stackrel{heat}{\to }M{g}_3{N}_2$

$\text{Final answer:}$

$MgO$ and $M{g}_3{N}_2$ are formed


$\text{Reaction of quick lime with silica}:$

Quick lime$\left(CaO\right)$ heated with silica $\left(Si{O}_2\right)$ to form calcium silicate$\left(CaSi{O}_3\right)$.
Involved reaction follow as:

$CaO+Si{O}_2\stackrel{heat}{\to }CaSi{O}_3$

$\text{Final answer}:CaSi{O}_3$ is formed


$\text{Reaction of chlorine with slaked lime}:$

When chlorine is added to slaked lime, $Ca(OH{)}_2$, it gives bleaching powder.


$\text{Final answer}:CaOC{l}_2$ is formed


$\text{Reaction of calcium nitrate with heat}:$

Calcium nitrate, on heating, decomposes to give calcium oxide.
Involved reaction follow as:

$2Ca\left(N{O}_3{)}_2\right(s)$

$\downarrow heat$

$2CaO\left(s\right)+4N{O}_2\left(g\right)+O_2\left(g\right)$

$\text{Final answer}:CaO$ is formed