Home
Class 11
CHEMISTRY
Alkali metals on combustion in excess of...

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 ?

A

Potassium superoxide `KO_2`

B

Soda lime (NaOH + CaO)

C

Sodium monoxide `(Na_2O)`

D

Hydrated calcium sulphate `(CaSO_4 . H_2O)`

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Similar Questions

Explore conceptually related problems

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:

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

Stability of + 1 oxidation state increases in the sequence-

Explain why the peroxides and superoxides of the alkali metals act as strong oxidising agents.

Metallic oxides are generally

Which of the following oxides is formed when potassium metal is burnt in excess air ?

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

Explain why lithium, sodium and potassium forms monoxide, peroxide and superoxide respectively.

Explain why : Lithium on being heated in air mainly forms the monoxide and not peroxide.

Potassium super oxide is used in space and submarines because it: