Lithium forms monoxide, sodium gives peroxide while the rest of the alkali metals form superoxide mainly when treated with an excess of air. Explain.

The thermal stability order of following carbonates:

${\mathrm{BeCO}}_3, {\mathrm{MgCO}}_3, {\mathrm{CaCO}}_3 {\mathrm{SrCO}}_3, {\mathrm{BaCO}}_3$

Write the products of the following reactions:
${\mathrm{NaHCO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4⟶$
${\mathrm{Na}}_2{\mathrm{CO}}_3+\mathrm{Ca}(\mathrm{OH}{)}_2⟶$
${\mathrm{NaHCO}}_3+\mathrm{NaOH}\to$

 $2{\mathrm{NaHCO}}_3\frac{\mathrm{\Delta }}{\text{ Boil }}$
${\mathrm{NaHCO}}_3+{\mathrm{CaCl}}_2\stackrel{\text{ room temperature }}{⟶}$