Chemical Bonding and Molecular Structure Part 1

Note:
(1) Bond length ∝‌

1

‌ Bond order ‌

(2) Bond order =‌

1

2

[Nb−Na]
Nb= No of electrons in bonding molecular orbital
Na= No of electrons in anti bonding molecular orbital
(4) upto 14 electrons, molecular orbital configuration isHere Na= Anti bonding electron =4 and Nb=10
(5) After 14 electrons to 20 electrons molecular orbital configuration isHere Na=10
and Nb=10
In 0 atom 8 electrons present, so in O2,8×2=16 electrons present.
Then in O2+no of electrons =15
in O2−no of electrons =17
in O22− no of electrons =18
∴ Molecular orbital configuration of O2 (16 electrons) is
∴Na=6
Nb=10
∴‌‌BO=‌

1

2

[10−6]=2
Molecular orbital configuration of O2+(15 electrons) is
‌∴‌‌Nb=10
‌Na=5
‌∴‌‌BO=‌

1

2

[10−5]=2.5
Molecular orbital configuration of O22+ (14 electrons) is
‌∴‌‌Nb=10
‌Na=4
‌∴‌‌BO=‌

1

2

[10−4]=3
Molecular orbital configuration of O2−(17 electrons) is
‌∴‌‌Nb=10
‌Na=7
‌∴‌‌BO=‌

1

2

[10−7]=1.5
Molecular orbital configuration of O22− (18 electrons) is
‌∴‌‌Nb=10
‌Na=8
‌∴‌‌B0=‌

1

2

[10−8]=1
As Bond length ∝‌

1

‌ Bond order ‌

So O22+ has the shortest bond length.