Select all constitutional isomers of C6H6.

Select all constitutional isomers of C6H6.

The Correct Answer and Explanation is:

The molecular formula C6H6 corresponds to benzene (C6H6) and its constitutional isomers. However, when considering constitutional isomers, we are looking for compounds that have the same molecular formula but different connectivity of atoms.

For C6H6, there are three main constitutional isomers that can exist by altering the arrangement of the carbon atoms in the benzene ring:

1. Benzene (C6H6) – This is the parent compound and is the simplest structure of C6H6, where all six carbon atoms are connected in a hexagonal ring with alternating single and double bonds between them. It is an aromatic compound known for its stability and resonance.
2. Cyclohexatriene – This is an alternate name for benzene, but it is a different way of conceptualizing the same structure. This compound involves the same six carbon atoms in a hexagonal ring with alternating single and double bonds. The structure is symmetrical, and it maintains the same molecular formula and resonance characteristics as benzene.
3. Phenylacetylene (C6H5C≡CH) – This compound is also a constitutional isomer of C6H6. It involves a benzene ring (C6H5) attached to an acetylene group (C≡CH). This is an example of how a triple bond can replace a part of the benzene ring’s alternating double bonds while maintaining the same molecular formula.

These three compounds are constitutional isomers because they share the same molecular formula (C6H6) but differ in the way the atoms are connected. Benzene itself is a very stable structure, but derivatives like phenylacetylene can introduce different types of bonding or functional groups while maintaining the same molecular formula.

It’s important to note that while C6H6 can have different resonance forms, only these three represent distinct ways of arranging atoms with the same molecular composition.