Lithium forms monoxide while sodium forms peroxide in the presence of excess oxygen----Why?

Lithium forms monoxide, sodium gives peroxide while the rest of the alkali metals form superoxide. Explain

Alkali metals on combustion in excess of air form different type of oxides depending on the size of metal cations e.g . lithium forms mainly the oxide Li_2O , sodium forms peroxide and some super oxides NaO_2 and potassium, Rubidium and caesium form the superoxides, MO_2 . The stability of peroxide and superoxide increases, as the size of the metal cation increases because of the stabilisation of larger anion by larger cations through lattice energy effect. These oxides are easily hydrolysed by water. The oxides and the peroxides are colourless when pure, but the superoxides are yellow or orange in colour. Peroxide and superoxide of sodium and potassium are widely used as oxidising agent and as air purifier in space capsules, submarines and breathing mask. When sodium reacts with excess of oxygen at 350^@ C , the oxidation number of oxygen per atom changes from:

Alkali metals on combustion in excess of air form different type of oxides depending on the size of metal cations e.g . lithium forms mainly the oxide Li_2O , sodium forms peroxide and some super oxides NaO_2 and potassium, Rubidium and caesium form the superoxides, MO_2 . The stability of peroxide and superoxide increases, as the size of the metal cation increases because of the stabilisation of larger anion by larger cations through lattice energy effect. These oxides are easily hydrolysed by water. The oxides and the peroxides are colourless when pure, but the superoxides are yellow or orange in colour. Peroxide and superoxide of sodium and potassium are widely used as oxidising agent and as air purifier in space capsules, submarines and breathing mask. Which of the following compound is used in the emergency breathing apparatus ?

Name the alkali metals which form superoxides when heated with excess oxygen.

Which of the following does not form an amine even in presence of excess ammonia -

Seedless fruits are formed in presence of hormone-

Which one of the following is not formed when a mixture of methyl bromide and bromobenzene is heated with sodium metal in the presence of dry ether ?

Lithium on being heated in air mainly forms the monoxide and not the peroxide. Why?

Which of the following compounds or pair of compounds is responsible for turning yellow sodium peroxide white in presence of air-

Addition of HBr to propene yields 2-bromopropane while in the presence of benzoyl peroxide the same reactions gives 1-bromopropane explain and give mechanism.