14.2 Further Aspects of Bonding

Benzene, C₆H₆, has two resonance structures. Draw skeletal formulae of these two structures.

Benzene is commonly drawn in the following manner:

Some of the sigma bonds in benzene are formed from hybrid orbitals. The type of hybridisation present is sp².

The sp² hybridized orbitals form sigma bonds in the benzene molecule. The delocalised electrons from pi bonds.
 

Deduce the number of sigma () bonds in benzene.

[1]

Deduce the number of pi () bonds in benzene.

[1]

Ozone, O₃, forms two resonance structures, shown below:

 

Allocate formal charges to the oxygen atoms in the left-hand diagram.

[1]

Deduce the bond order for the O-O bond in ozone.

The bond order of oxygen, O₂, molecules is 2.

 

State which bonds are easier to break, those in oxygen or those in ozone.

Compare the wavelengths of light needed to break the bonds in oxygen and ozone respectively

Ozone, O₃, can react to form oxygen, O₂. Write an equation to show the overall equation for this depletion.

A number of species can catalyse the depletion of ozone, O₃.

Write the molecular formulae for two catalysts of ozone depletion.

Methane contains sp³ hybridised orbitals.

Explain the formation of sp³ hybridised orbitals.

How many sp³ hybridised orbitals are present in methane?

Ethyne, C₂H₂, is another hydrocarbon, in this case containing sp hybrid orbitals.

 

Explain the formation of the sp hybrid orbitals in ethyne

Deduce the number of sp hybrid orbitals in a molecule of ethyne.

[1]

State if these sp hybrid bonds form sigma (σ) or pi (π) (bonds)

Explain, using the concept of hybridisation, how the triple bond in ethyne, C₂H₂, forms.

Ethanenitrile, CH₃CN, is an organic molecule with a tetrahedral molecular geometry around one carbon and a linear molecular geometry around the other carbon. The structure is shown below:

Identify how many sp³ hybrid orbitals are present in this molecule.

Identify how many sp hybrid orbitals are present in this molecule.