Chemistry - s Block Elements Question with Solution | TestHub

The reactions can be summarised as follows :

$\text{A}\stackrel{\Delta }{\to }\text{Colourless gas}+\text{residue}$

$\text{Residue}+{\text{H}}_2\text{O}\to \text{B}\stackrel{{\text{Excess CO}}_2}{\to }\text{C}\stackrel{\Delta }{\to }\text{A}$

This is possible only when A is CaCO₃. The reactions are as follows :

$\begin{array}{ccccc}{\text{CaCO}}_3& \stackrel{\Delta }{\to }& {\text{CO}}_2& +& \text{CaO}\\ \left(\text{A}\right)& & \left(\text{Colourless gas}\right)& & \left(\text{Residue}\right)\end{array}$

$\begin{array}{ccccccccc}\text{CaO}& +& {\text{H}}_2\text{O}& \to & \text{Ca}{\left(\text{OH}\right)}_2& \underset{\left(\text{excess}\right)}{\overset{{\text{CO}}_2}{\to }}& \text{Ca}{\left({\text{HCO}}_3\right)}_2& \stackrel{\Delta }{\to }& {\text{CaCO}}_3\\ & & & & \left(\text{B}\right)& & \left(\text{C}\right)& & \left(\text{A}\right)\end{array}$