Question

$C{H}_2=C=O$
The hybridisation state of middle carbon atom is:

• A. sp
• B. $s{p}^2$
• C. $s{p}^3$
• D. none

Answer 1

Answer: (A)

sp

It is evident that the central atom (middle carbon atom) forms 2 sigma bonds and 2 pi bonds. The pi bonds are formed by the overlap of unhybridized p-orbitals. We know, that the number of hybrid orbitals formed = number of atomic orbitals taking part. Since the central atom forms two sigma bonds there are two sidewise overlapping. So, there are two hybrid orbitals which overlaps with other orbitals to form two sigma bonds.
Thus, there are two atomic orbitals taking part.
Therefore, state of hybridization of the middle carbon atom is sp.