Question
Question: Consider following statements (i) Bond order of CO and \({N_2}\) is same (ii) \({O_2}^ + \) is m...
Consider following statements
(i) Bond order of CO and N2 is same
(ii) O2+ is more stable than O2
(iii) Bond order of CO+ and N2+ are same
(iv) MOT explain diamagnetic character of oxygen
(v) HOMO of F2 molecule is σ2pz∗
Correct statements are
Solution
The formula to find the bond order of the species is as below.
Bond order = 2No. of electrons in bonding orbitals - No. of electrons in antibonding orbitals
Complete step by step solution:
We will check all the given statements to check whether they are correct or not.
(i) The electronic configuration of molecular orbitals in CO is: σ1s2,σ∗1s2,σ2s2,σ∗2s2,π2py2,π2pz2,σ2px2
- We know that orbitals which have * sign shows antibonding orbital. The formula to find the bond order is as below.
Bond order = 2No. of electrons in bonding orbitals - No. of electrons in antibonding orbitals
Bond order = 210−4=6
Now, for N2 the electronic configuration of its molecular orbitals can be given as σ1s2,σ∗1s2,σ2s2,σ∗2s2,π2py2,π2pz2,σ2px2 .
Now, we put the available values into the formula of bond order, we get
Bond order = 210−4=6
Thus, the bond order of both species is the same and this statement is right.
(ii) We will see the molecular orbital configuration of both O2+ and O2 to find their bond order. Then we can say that the compound which has higher bond order, will be more stable.
M.O configuration of O2+ : σ1s2,σ∗1s2,σ2s2,σ∗2s2,σ2px2,π2py2,π2pz2,π∗2py1
So, bond order = 210−5=2.5
M.O. configuration of O2 : σ1s2,σ∗1s2,σ2s2,σ∗2s2,σ2px2,π2py2,π2pz2,π∗2py1,π∗2pz1
So, bond order = 210−6=2
Thus, we can say that as O2+ has higher bond order, it is a more stable species.
(iii) The M.O. configuration of CO+ is : σ1s2,σ∗1s2,σ2s2,σ∗2s2,π2py2,π2pz2,σ2px1
M.O. configuration of N2+ is : σ1s2,σ∗1s2,σ2s2,σ∗2s2,π2py2,π2pz2,σ2px1
As, both species have the same M.O. configuration, they will have same bond order and it will be 29−4=2.5
(iv) No, according to MOT, actually O2 is a paramagnetic molecule because it has two unpaired electrons in its structure. The M.O configuration of O2 is σ1s2,σ∗1s2,σ2s2,σ∗2s2,σ2px2,π2py2,π2pz2,π∗2py1,π∗2pz1 .Thus, this statement is not correct.
(v) HOMO stands for highest occupied molecular orbital. We will take a look at MO configuration of F2 to find its HOMO.
MO configuration of F2 = σ1s2,σ∗1s2,σ2s2,σ∗2s2,σ2pz2,π2px2,π2py2,π∗2px2,π∗2py2
Thus, we can see that the highest occupied molecular orbital is π∗2py orbital. Thus, the given statement is not correct.
Therefore, statements (i), (ii) and (iii) are correct.
Note: The compound which has an unpaired electron in its MO diagram is called a paramagnetic compound. The compound which does not have any unpaired electron in MO diagram is called diamagnetic compound.