Question

How many atoms are $s{p}^2$ hybridised in 7-ethyl-3-nonen-2,5,8-tricarboxylic acid?

Answer 1

Two p orbitals and one s orbital combine to form 3 equivalent orbitals then the hybridization is known as sp² hybridization.

All three carbon of three $-COOH$ are $s{p}^2$.
Three oxygen, one in each $-COOH$ are $s{p}^2$.

Both C-3 and C-4 carbons are $s{p}^2$.

Hence, 8 atoms are sp² hybridized in the compound 7-ethyl-3-nonene-2,5,8- tricarboxylic acid.