Question

Write the electronic structure of Acetylene.

Answer 1

Hint: The bonding in the compound takes place in an order to complete it octet with respect to the atoms involved by the sharing of electrons between them. This further determines the number and type of bonds formed in the structure to attain a stable geometry.

Complete step by step answer:
The electronic structure of the given compound can be obtained by using its electronic configuration. As we know the molecular formula of acetylene is ${{C}_{2}}{{H}_{2}}$, consisting of two bonded carbon atoms, which are further bonded to a hydrogen atom. The electronic configuration of the carbon atom is $1{{s}^{2}}2{{s}^{2}}2{{p}^{2}}$. In its excited state, one electron from 2s orbitals jumps to the 2p orbital. In order to form a bond with the adjacent carbon and the hydrogen, it undergoes hybridisation to form two sp-hybridised orbitals. Thus, forming two sigma bonds along the internuclear axis in the structure. The two p-orbitals (${{p}_{x}},{{p}_{y}}$) which are perpendicular to the internuclear axis, undergo sideways overlapping with the p-orbitals of the adjacent carbon atom to form two pi-bonds. Thus, we have a triple bond formed between the two carbon atoms. Also, the octet is complete for all the atoms present in the structure.

The acetylene formed is an unsaturated hydrocarbon. It is the simplest alkyne compound, with its IUPAC name as ethyne. From its sp- hybridisation and bonding, all the four atoms are in a straight line. Thus, having a linear geometry.

Note: The electronic configuration through which the hybridisation can be determined with respect to the number of bonds formed. The structure can thus be obtained.