The total number of π bonds in the H-C≡C-C≡C-C≡N molecule is ________.
A)3
B)4
C)6
D)9
E)12

Question

Quizplus · Accepted Answer

A π bond is formed between two atoms when there is a side-to-side overlap of their p-orbitals. In the given molecule, between H and C there is only a single bond (made up of a σ bond), while between C and N there is a triple bond (made up of one σ bond and two π bonds). Therefore, the total number of π bonds present in the molecule is equal to the number of triple bonds, which is 2. There are 3 triple bonds in the given molecule, so the total number of π bonds is 6. Hence, the correct answer is (C).

The Total Number of π Bonds in the H-C≡C-C≡C-C≡N Molecule