Question

Given, $N{a_2}{O_2}$ has light yellow colour. This is due to
a.) presence of unpaired electron in the molecule
b.) presence of trace of $Na{O_2}$
c.) presence of $K{O_2}$ as an impurity
d.) none of above

Answer 1

Hint: The sodium peroxide is a peroxide of alkaline metals and we know that the alkaline metal peroxides have unpaired electrons and the transition of these unpaired electrons give them visible colour.

Complete answer:
We all know that Sodium is an alkaline metal. It belongs to group 1 and s- block.
This strong base is a metal peroxide. It is yellow in colour due to the presence of unpaired electrons in the molecule.
When these unpaired electrons absorb some energy, these get excited and then show colours which are in visible range.
The peroxide has yellow -white to yellow colour which is due to presence of unpaired electrons.

Thus, the correct option is option a.).

Additional information:
Sodium peroxide can be prepared by treating sodium hydroxide with hydrogen peroxide. We can also prepare by reaction of metallic sodium with oxygen. This peroxide crystallizes with hexagonal symmetry. It reacts readily with water.
Further, it is soluble in acid but insoluble in base.

Note:
Earlier, sodium peroxide was used to bleach wood pulp to produce paper and textiles. It is used now to extract minerals from various ores. It is used as an oxidizing agent. We can also produce oxygen by reacting it with carbon dioxide. The products are oxygen along with sodium carbonate.