Question

What is the hybridization of the carbon atom in the acetylene molecule?

Answer 1

Concept of hybridization:

• With increase in s-character, bond strength increases consequently and bond length decreases.
• So, the increasing order of bond length of different hybrid orbitals is given below:

Hybridization of acetylene molecule:

• During hybridization, the sigma bond is formed when one $\mathrm{sp}$ orbital overlaps with each carbon atom, and two $\mathrm{C}-\mathrm{H}$ bonds are formed when the second $\mathrm{sp}$ orbital on each carbon overlaps with the $1\mathrm{s}$orbital of $\mathrm{H}$.
• In this, the carbon atom has two $2\mathrm{p}$ orbitals that are half-filled.
• Here, the $\mathrm{p}$ orbitals participate in triple bond formation.
• Thus, the hybridization of acetylene molecule is $\mathrm{sp}$ hybridization and has linear geometry.