CBSE Class 11-science Answered

Electronic configurations:

O₂ = ? 1 s²  ?*1 s²  ?2 s² ?*2 s²  ?2 p ² _z (?2p ² _x  ?2 p ² y )  (?*2 p ¹ x = ?*2 p¹ y )  

O₂⁺ = ? 1 s²  ?*1 s²  ?2 s² ?*2 s²  ?2 p ² _z (?2p ² _x  ?2 p ² y )  ?*2 p ¹ x

O₂ ^- = ? 1 s²  ?*1 s²  ?2 s² ?*2 s²  ?2 p ² _z (?2p ² _x  ?2 p ² y )  (?*2 p ¹ x = ?*2 p¹ y ) ?*2 p¹ z

O₂ ^2-  = ? 1 s²  ?*1 s²  ?2 s² ?*2 s²  ?2 p ² _z (?2p ² _x  ?2 p ² y )  (?*2 p ¹ x = ?*2 p¹ y ) ?*2 p² z 

The electronic configuration of the O₂ ⁺ ion containing 15 electrons can be written as:

? 1 s²  ?*1 s²  ?2 s² ?*2 s²  ?2 p ² _z (?2p ² _x  ?2 p ² y )  (?*2 p ¹ x = ?*2 p y )  ?*2 p z

The bond order can be found as:

B.O = (N_b-N_a)/2

N_b = Number of electrons in the bonding orbitals = 10

N_a = Number of electron in the anti-bonding orbitals = 5

B.O = (10-5)/2 = 5/2 = 2.5

The electronic configuration of the O₂ ^- ion containing 17 electrons can be written as:

? 1 s² < ?*1 s² < ?2 s² < ?*2 s² < ?2 p ² _z < (?2p ² _x = ?2 p ² y ) < (?*2p ² x = ?*2 p ¹ y ) < ?*2 p z

The bond order can be calculated as:

B.O = (10-7)/2 = 3/2 = 1.5

Similarly, Bonbd order of O₂ is = B.O = (10-6)/2 = 4/2 = 2

Bonbd order of O₂ ^2- is = B.O = (10-8)/2 = 2/2 = 1

The higher the value of bond order, higher is the stability of the bond, so on the basis of above information, we can say that, O₂ ⁺ ion is more stable than O₂,  O₂ ^- and O₂^2- ions.