Question

Indicate the kind of molecular orbital (σ ,σ ^*,π ,π ^*) that results when the two atomic orbitals are combined:

Short answer

a.π ^*

b.π

c.σ

d.σ ^*

Step-by-step solution

Understanding orbital interaction

Orbitals interact with each other to form bonding and anti-bonding molecular orbitals. In the case of constructive or in-phase interaction bonding, molecular orbitals are formed. When destructive or out-of-phase interaction takes place, anti-bonding molecular orbitals are formed.

Finding out the MO formed in Subpart (a)

In case of p-orbitals, there can be two types of overlap which are side-on or lateral overlap that forms π or π ^*and head-on overlap which forms σ andσ ^* MO.As here we can see out of phase lateral or side-on overlap of p-orbitals thus MO formed is.π ^*

Finding out the MO formed in Subpart (b) 

Here also, in the case of p-orbitals, two types of overlap which are side-on or lateral overlap that forms π or π ^* and head-on overlap which forms and σ andσ ^* MO.

Here, is an in-phase lateral or side-on overlap of p-orbitals thus MO formed isπ .

Finding out the MO formed in Subpart (c)

In case of s–orbitals as they are spherically symmetrical there is only one type of overlap which mostly forms σ andσ ^* MO.

In this part we find anin-phase head-on overlaptaking place between s and p orbital. Thus, MO formed is .σ ^*