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Bonding in organic molecules
Concepts tested here
- Counting pi electrons
- Counting sigma and pi bonds
All Questions
2015 AIPMT-I 2 questions
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The enolic form of ethyl acetoacetate as below has:
Enol form: $CH_3-C(OH)=CH-COOC_2H_5$ ($C_6H_{10}O_3$, 19 atoms, open chain).
Number of $\sigma$ bonds in an acyclic molecule = atoms − 1 = 18.
$\pi$ bonds: one C=C and one C=O, so 2.
So the enol form has 18 $\sigma$ and 2 $\pi$ bonds. -
The total number of $\pi$-bond electrons in the following structure is:
The structure has 4 C=C double bonds, i.e. 4 $\pi$ bonds.
Each $\pi$ bond has 2 electrons, so total $\pi$-bond electrons = 8.