NEETChemistryChemical Bonding and Molecular Structure
The total number of sigma ( ) and pi ( ) bonds in the molecule 1,1 -dicyanoethylene, represented by the condensed formula CH ₂ =C(CN) ₂ , is:
Options
- A9 bonds and 5 bonds
- B7 bonds and 5 bonds
- C7 bonds and 3 bonds
- D5 bonds and 5 bonds
Correct answer
B. 7 bonds and 5 bonds
Step-by-step solution
The expanded structural formula of 1,1 -dicyanoethylene is H ₂ C=C(C N) ₂ . To find the total number of bonds, we count all the single bonds and one bond from each multiple bond: 2 C-H single bonds = 2 1 C=C double bond = 1 2 C-C single bonds = 2 2 C N triple bonds = 2 Total bonds = 2 + 1 + 2 + 2 = 7 . Alternatively, for an acyclic molecule, the number of bonds is (Total atoms - 1 ). The molecule has 4 C, 2 H, and 2 N atoms ( 8 atoms total), giving 8 - 1 = 7 bonds. To find the total number of bonds, we count the re