Question

Mention the hybridised state of carbonyl carbon atom.

Answer 1

This is the structure of carbonyl carbon where the carbon is attached with one double bond with oxygen and two single bonds.
If a carbon is attached with all single bonds it is $s{p}^3$ hybridized.
If a carbon is attached with one double bond it is $s{p}^2$ hybridized.
If a carbon is attached with one triple bond or two double bonds it is $sp$ hybridized.
Hence, the carbonyl carbon is $s{p}^2$ hybridized.