Why is that on being heated in excess supply of air K,Rb and Cs forms superoxide’s instead of Oxides & peroxides?

Why is that on being heated in excess supply of air K,Rb and Cs forms superoxide’s instead of  Oxides & peroxides?
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1 Answer

Answer :

Ans.K + ,Rb+ and Cs+ are large cations and superoxide ion is larger than oxide and peroxide ions. Since due to higher lattice energies,a large cation stabilizes a large anion,therefore these metals form Superoxides.
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