Question

Hybridisation of the carbon atom of carbonyl group is

• A. $\mathrm{sp}$
• B. ${\mathrm{sp}}^2$
• C. ${\mathrm{sp}}^3$
• D. ${\mathrm{sp}}^3{\mathrm{d}}^2$

Answer 1

The correct option is B

${\mathrm{sp}}^2$

Explanation for Correct Option:-

Option (B): ${\mathrm{sp}}^2$

• The structure of carbonyl groups are:

• From the structure we can see that Carbon and Oxygen have a double between them and there are 2 bonds left for carbon to be bonded with
• So carbon can bond with three different atoms, which makes the hybridisation of it as ${\mathrm{sp}}^2$.
• Hence it is the correct option.

Explanation for Incorrect Option:-

Option (A): $\mathrm{sp}$

• There is a double bond between carbon and oxygen in the carbonyl group along with 2 single bonds of the carbon atom.
• $\mathrm{sp}$ hybridisation menas carbon has only 2 bonds present in the carbonyl group, which is not true, as it can bond with three different atoms.
• This result in the hybridisation of ${\mathrm{sp}}^2$ not $\mathrm{sp}$
• Hence it is the incorrect option.

Option (C): ${\mathrm{sp}}^3$

• Carbon and Oxygen have a double between them and there 2 bonds left for carbon to be bonded with.
• ${\mathrm{sp}}^3$ hybridisation means, there are 4 different atoms bonded with carbon, which is not possible as after the double bonding with oxygen it has only 2 bonds left.
• Thus its hybridisation should be ${\mathrm{sp}}^2$ not ${\mathrm{sp}}^3$
• Hence it is the incorrect option.

Option (D): ${\mathrm{sp}}^3{\mathrm{d}}^2$

• ${\mathrm{sp}}^3{\mathrm{d}}^2$means carbon has a total of 6 different bonds.
• This is not possible as carbon can make a maximum of 4 bonds due to the presence of 4 valence electrons in its outermost shell.
• Thus its hybridisation should be ${\mathrm{sp}}^2$ not ${\mathrm{sp}}^3{\mathrm{d}}^2$
• Hence it is the incorrect option.

Therefore, Hybridisation of the carbon atom of carbonyl group is option (B) ${\mathrm{sp}}^2$