Question

5.Calculate the number of sigma and pie bonds in:
CH2=C=CHCH3​

Answer 1

Answer:

sigma C−C bonds =3, sigma C−H bonds =6, pi C−C bonds =2 

Explanation:

Sigma bonds (σ) are formed by the coaxial overlapping of the two orbitals of equal energies. Generally, the single bonds are sigma bonds. Pi bonds (π) are formed by the lateral overlapping of two orbitals with equal energies. Double bond contains one sigma bond and one pi bond whereas triple bond contains one sigma bond and two pi bond. Here, sigma C−C bonds =3, sigma C−H bonds =2+1+3=6 , pi C−C bonds =1+1=2.

Answer 2

Answer:

Total no.of σ bonds: 9

Total no.of π bonds: 2

Explanation:

A single bond consists of only a sigma bond. A double bond consists of sigma and a pi bond.

So, the formula is: CH2=C=CH-CH3

2 double bonds are there. So, 2 sigma and 2 pi bonds.

+

CH2- 2 sigma bonds

CH- 1 sigma bond

CH-CH3- 1 sigma bond

CH3- 3 sigma bonds

Total no. of sigma bonds: 2+2+1+1+3 = 9 sigma bonds

Total no. of pi bonds: 2

Tricks:

• If you are given with the condensed form, split it and write in complete form. Then, count the no.of sigma and pi bonds.

• Pi bonds are present only in double bonds(=) or triple bonds(≡)

• One sigma bond is present in all the 3 bonds.

• 1 pi and 2 pi bonds are present in double and triple bonds respectively.