Question

Potassium on exposure to air gives:
This question has multiple correct options
A. Potassium peroxide
B. Potassium superoxide
C. Potassium dioxide
D. Potassium oxide

Answer 1

Hint: As we know that potassium is an extremely active metal which is found to react violently with oxygen in air. It is also found that potassium oxidizes very fast as compared to most metals and forms oxides that are with oxygen-oxygen bonds.

Complete Solution :
- It is found that Potassium on exposure to air forms three products that are: Potassium oxide, Potassium peroxide and Potassium superoxide. We can see the reaction that takes place when potassium is exposed to air:
\[8K+4{{O}_{2}}\to 2{{K}_{2}}O+2K{{O}_{2}}+{{K}_{2}}{{O}_{2}}\]

- As we can see from the above reaction that Potassium oxide is formed which is an ionic compound, pale yellow solid and is a highly reactive compound. Potassium peroxide is also formed in the reaction which is very important as it reacts with water to form potassium hydroxide and oxygen.
- Potassium superoxide is basically a paramagnetic solid that decomposes in moist air. It is also found to be used as a carbon dioxide scrubber anion.
- Hence, we can conclude that this question has multiple correct options (a), (b), (d) that are Potassium oxide, Potassium peroxide and Potassium superoxide
So, the correct answer is “Option A, B, and D”.

Note: - We must not get confused in three terms oxide, peroxide and superoxide. As an oxide is a chemical compound that mainly contains at least one oxygen atom and one other element in its chemical formula. Peroxide is a compound that basically contains the peroxide anion or oxygen-oxygen single bond.
- Whereas, a superoxide is a compound that contains the superoxide anion.