consider the molecule tetracyanoethylene: :n≡c :n≡c c=c c≡n: c≡n: part 1 of 2 how many sigma bonds are there…

consider the molecule tetracyanoethylene: :n≡c :n≡c c=c c≡n: c≡n: part 1 of 2 how many sigma bonds are there in the tetracyanoethylene molecule? part 2 of 2 how many pi bonds are there in the tetracyanoethylene molecule?
Answer
Explanation:
Step1: Analyze single - bonds
Single - bonds are all sigma bonds. In the tetracyanoethylene molecule, count the single C - C and C - N single bonds. There are 4 C - C single bonds and 4 C - N single bonds.
Step2: Analyze double - and triple - bonds
A double - bond consists of 1 sigma and 1 pi bond, and a triple - bond consists of 1 sigma and 2 pi bonds. The central C = C double - bond contributes 1 sigma bond, and each of the 4 C≡N triple - bonds contributes 1 sigma bond. The total number of sigma bonds is (4 + 4+1 + 4=9).
Step3: Analyze pi - bonds
The central C = C double - bond contributes 1 pi bond, and each of the 4 C≡N triple - bonds contributes 2 pi bonds. The total number of pi bonds is (1+4\times2 = 9).
Answer:
Part 1 of 2: 9 Part 2 of 2: 9