Which one of the following is thermally most stable

A) Thermal stability, solubility and basic strength

LiOH<NaOH<KOH<RbOH<CsOH…..LiOH is the only weak base of the family ;

They are colourless crystalline solids.

B) All alkali metal hydroxides are deliquescent. They exist as MOH.xH₂O;

    Due to hydration a lot of heat is liberated ;

C) MO₂(super oxides) are paramagnetic with one unpaired electron in pi anti bonding molecular orbital;

    MO₂(super oxides) are yellow (or) orange in colour ;

    Lithium forms monoxides

   Sodium with limited oxygen forms monoxide and with excess oxygen forms peroxide;

   K, Rb and Cs form super oxides. Stability of super oxides increases with increase in cation size. This fact is explained by    Lattice enthalpy effects.

D) Na₂O₂ is a good oxidizing agent in inorganic chemistry.

$$\begin{gathered} \mathrm{E}) {\mathrm{M}}_2\mathrm{O}+{\mathrm{H}}_2\mathrm{O}\to 2\mathrm{MOH} ; \\ {\mathrm{M}}_2{\mathrm{O}}_2+2{\mathrm{H}}_2\mathrm{O}\to 2\mathrm{MOH}+{\mathrm{H}}_2{\mathrm{O}}_2 ; \\ 2{\mathrm{MO}}_2+2{\mathrm{H}}_2\mathrm{O}\to 2\mathrm{MOH}+{\mathrm{H}}_2{\mathrm{O}}_2+{\mathrm{O}}_2; \end{gathered}$$