Sodium is heated in excess of air, free from ${\mathrm{CO}}_2$ at ${35}^0\mathrm{C}$ to form X. X absorbs ${\mathrm{CO}}_2$ and forms ${\mathrm{Na}}_2{\mathrm{CO}}_3$ and Y. ‘X’ and ‘Y’ are respectively

$$\begin{gathered} 2\mathrm{Na} + {\mathrm{O}}_2\left(\mathrm{air}\right) \stackrel{{350}^0\mathrm{C}}{\to } {\mathrm{Na}}_2{\mathrm{O}}_2 \left(\mathrm{X}\right) \\ 2{\mathrm{CO}}_2 + 2{\mathrm{Na}}_2{\mathrm{O}}_2 \stackrel{ }{\to } 2{\mathrm{Na}}_2{\mathrm{CO}}_3 + {\mathrm{O}}_2 \left(\mathrm{Y}\right) \\ \mathbf{Note}\mathbf{ }\mathbf{:}\mathbf{ }{\mathrm{Na}}_2{\mathrm{O}}_2 + {\mathrm{O}}_2 \underset{300 \mathrm{atm}}{\overset{{450}^0\mathrm{C}}{\to }} 2 {\mathrm{NaO}}_2 \\ \mathrm{Na} + {\mathrm{O}}_2 \left(\mathrm{limited} \mathrm{amount}\right) \stackrel{{180}^0\mathrm{C}}{\to } {\mathrm{Na}}_2\mathrm{O} \end{gathered}$$