Question

 Consider two 2p orbitals, one on each of two different atoms, oriented side-to-side, as in the figure. Imagine bringing these nuclei together so that overlap occurs as shown in the figure. This overlap results in a system of molecular orbitals. (Scroll down to answer part "c)".)

 a) Below, construct an orbital interaction diagram for molecular orbital formation by dragging the images triat represent various orbital types (e.g., atomic, bonding, antibonding) into the relevant boxes.

 b) Identify the number of nodes in each atomic and molecular orbital.

 c) When two electrons occupy the bonding molecular orbital above, what type of bond results? Explain.

• because the two electrons are in a σ bonding molecular orbital.
  

•  because only one bond forms.

• because the bond is not cylindrically symmetrical about the internuclear axis.

• because p orbitals can never form o bonds.
  

Answer 1

Concepts and reason

The concepts used to solve this problem are molecular orbital diagram and nodes.

Molecular orbitals represent the region where electron can be found in a molecule. Molecular energy diagram is the energy profile diagram of molecular orbitals. Nodes represents the region where the probability density function reduces to zero

Fundamentals

If the atomic orbitals can overlap and has similar energy and symmetry, they combine linearly to form molecular orbitals.

Probability of finding an electron in the nodal plane is zero

Part a

Atomic orbitals are represented as:

Bonding orbital is represented as:

Antibonding orbital is represented as:

The molecular orbital diagram is represented as:

Part b

Calculate number of nodes $\left( {{n_t}} \right)$ as follow:

${n_t}\; = \;n - 1$

For 2p orbital, substitute 2 for $n$ , thus,

$\begin{array}{c}\\{n_t}\; = \;2 - 1\\\\ = 1\\\end{array}$

Node in 2p bonding orbital is as follows:

Nodes is 2p antibonding orbital is as follows:

Part c

When two electrons occupy the bonding molecular orbital, bond results in the formation of ${\rm{\pi }}$ bond.

Ans: Part a

Molecular orbitals diagram is represented as:

Part b

Number of node in 2p orbital is 1.

Number of node in bonding orbital of 2p is 1.

Number of nodes in antibonding 2p orbital is 2.

Part c

When two electrons occupy the bonding molecular orbital, bond results in the formation of ${\rm{\pi }}$ bond because the bond is not cylindrically symmetrical about the internuclear axis.