Alkali and alkaline earth metals react with oxygen to form oxides, peroxides, an

Question

Alkali and alkaline earth metals react with oxygen to form oxides, peroxides, and superoxides. (a) Indicate the most likely product for each of the Group I and Group II elements. (b) What physical factors are responsible for the relative stability of oxide vs. peroxide vs. superoxide? (c) Even if an oxide is the most stable product formed from reaction with O2 (typically the case for the alkaline earth metals), does that mean it is not possible to prepare peroxides or superoxides? Defend your choice.

Explanation / Answer

The alkali and alkaline earth metals burn in air to form oxide, peroxide, superoxides depending upon metals. Lithium forms monoxide Li2O and some peroxide Li2O2 , Na forms peroxide Na2O2 and some oxide Na2O, whereas other latter elements Gr-I form superoxides MO2 . All five Gr-I metals can form their corresponding oxide, peroxide, superoxide by dissolving metals with the liquid ammonia and appropriate amount of dioxygen.Berrilium peroxide BaO2, is possible and also calcim peroxide but they are prepared by drastic condition and product is very unstable. .The physical factors may be the atomic and ionic sizes ,lattice energy and attractive force between ions.Normally large atoms or ions form waeker bond than small ones. The peroxide and superoxide ions are large, and obviously the stabilty of these ions of corresponding metals increases, when metal ions become larger. Because large cations can stablised by large anions, Since they form a higher coordination number which gives high lattice energy.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.