Lithium forms monoide, sodium gives peroxide while the rest of the alkali form superoxides. Explain

Explain the following: (a) KO_2 is paramagnetic. (b) Lithium forms oxide, sodium forms peroxide while potassium and rubidium form superoxides. (c) BaO is soluble but BaSO_4 is insoluble in water.

Which of the following will form superoxide?

What kind of metals can form superoxides?

Alkali metals burn in air to form oxides, peroxides and superoxides. Lithium burns in moist air to form normal oxide as the major product. Some lithium nitride is also formed if nitrogen is present. Sodium loses lustre and forms both normal oxide and peroxide, the peroxide being the major product. Rest of all alkali metals form peroxides. All metals can be forced to form oxides, peroxides and superoxides by dissolving in liquid ammonia and bubbling appropriate amount of O_(2) . Which of the following oxides is the strongest oxidising agent :

Alkali metals burn in air to form oxides, peroxides and superoxides. Lithium burns in moist air to form normal oxide as the major product. Some lithium nitride is also formed if nitrogen is present. Sodium loses lustre and forms both normal oxide and peroxide, the peroxide being the major product. Rest of all alkali metals form peroxides. All metals can be forced to form oxides, peroxides and superoxides by dissolving in liquid ammonia and bubbling appropriate amount of O_(2) . Which among the following oxides turn red litmus paper blue :

Which metal will not form superoxide-