Question:

The compound formed upon combustion of potassium metal in excess air is

Updated On: Jun 3, 2024
  • $K_{2}O_{2}$
  • $ KO_{2}$
  • $K_{2}O$
  • $ KOH $
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

The compound formed upon combustion of potassium metal in excess air is potassium superqxide.
$K \stackrel{ O _{2}}{\longrightarrow} \underset{\text { Oxide }}{ K _{2} O } \stackrel{ O _{2}}{\longrightarrow} \underset{\text { Peroxide }}{ K _{2} O _{2}} \stackrel{ O _{2}}{\longrightarrow} \underset{\text { Superoxide }}{ KO _{2}}$
Was this answer helpful?
0
0

Concepts Used:

Group 1 Elements

Group one of alkali metals is s-block elements with just one electron in their s-orbital. They are are alkali metals. They are named so because of the alkaline nature of the hydroxides and oxides.

Alkali metals are characterized by one s-electron in the valence shell of their atoms.

Alkali metals have a corresponding [Noble gas] ns1 electronic configuration. They occupy the first column of the periodic table. Alkali elements are:

  • Lithium(Li)
  • Sodium(Na)
  • Potassium (K)
  • Rubidium (Ru)
  • Cesium (Cs)
  • Francium (Fr)

They have occupied successive periods from first to seven. Francium is a radioactive element with very low half-life.

Electronic Configuration:

  • Alkali metals have one electron in their valence shell.
  • The electronic configuration is given by ns1. For example, the electronic configuration of lithium is given by 1ns1 2ns1.
  • They tend to lose the outer shell electron to form cations with charge +1 (monovalent ions).

This makes them the most electropositive elements and due to the same reason, they are not found in the pure state.