Question
Question: Bond order of \({O_2}\) , \(O_2^ + \) , \(O_2^ - \) and \(O_2^{2 - }\) is in order ? A. \(O_2^ - <...
Bond order of O2 , O2+ , O2− and O22− is in order ?
A. O2−<O22−<O2<O2+
B. O22−<O2−<O2<O2+
C. O2+<O2<O2−<O22−
D. O2<O2+<O2−<O22−
Solution
We are provided with Oxygen molecules with different types of charge. We will first know what a bond order is. Then we will calculate the bond order of each molecule one by one. In the end we will arrange them in increasing order.
Formula Used: Bond Order: 21× [ Number of electron in A.MO. ] − [ number of electrons in bonding molecular orbitals]
Complete step-by-step answer:
Step-1 All the molecules possess bond order. The bond order changes from one molecule to another molecule. So we should look at what the bond order is.
Step-2 Bond order is the difference between the number of electrons in bonding molecular orbitals and the number of electrons in the anti bonding molecular orbital.
Step-3 The bond order is directly proportional to the bond strength. If the bond order is higher than there is greater pull between two atoms. The bond order is inversely proportional to the shorter length of bond.
1. For O2 :
O2 has a total 16 electrons in its orbitals. Molecular orbitals are completely full so they not participate in bonding
Electronic configuration of O2: (σ2s)2(σ2s∗)2(σ2p)2(π2P)4(π2P∗)2
So, bond order of O2= 21×[8−4] , ⇒Bond order of O2= 2
For O2− : O2− has a total 17 electrons in its orbitals. Molecular orbitals are completely full so they not participate in bonding
2. Electronic configuration of O2− : (σ2s)2(σ2s∗)2(σ2p)2(π2P)4(π2P∗)3
Bond order for O2− = 21×[8−5]
⇒Bond order for O2− = 1.5
For O2+ : O2+ has a total 15 electrons in its orbitals.
3. Electronic configuration of O2+ : (σ2s)2(σ2s∗)2(σ2p)2(π2P)4(π2P∗)1
Bond order for O2+ = 21×[8−3]
⇒Bond order for O2+ = 2.5
4. For O22− : O22− has a total 18 electrons in its orbitals .
Electronic configuration of O22− : (σ2s)2(σ2s∗)2(σ2p)2(π2P)4(π2P∗)4
Bond order for O22− = 21×[8−6]
⇒Bond order for O22− = 1
So we get the increasing order of the bond order of the Oxygen molecule.
O22−<O2−<O2<O2+ .
Note: Oxygen gas is a colorless, tasteless, odorless gas. It occurs in molecular nature. It is non metal. It is used for combustion. Still the pure oxygen does not burn. Till 1961 oxygen was used as standard for weighing the elements. The excess oxygen is even harmful to the body.