Question

How many σ bonds are there in each molecule ethane ethylene acetylene?

Answer 1

The  sigma  bonds  are  formed  when  orbitals  overlap  side  by  side  and  is  related  to  covalent  bond  In  ethylene  the number  of  sigma   bond  are  5.
Reason,  carbon  has  four  carbon -hydrogen  bond  which  form  four  sigma  bond.  The  other    sigma  bond  is  between  carbon=carbon  bond  thus  ethylene  has  5  sigma  bond

Answer 2

Explanation:

When there occurs head-on overlapping between the atomic orbitals then the bond formed is known as a sigma bond.

A sigma bond is represented by the symbol "$\sigma$". A compound with only single bonds between its atoms will have all the bonds as sigma bonds.

A double bond has one sigma and one pi bond. Whereas a triple bond will have one sigma and two pi bonds.

Hence, number of sigma bonds present in the given compounds will be as follows.

• As the chemical formula of ethane is $CH_{3}CH_{3}$ and it contains only single bonds. Hence, in a molecule of ethane there are 7 sigma bonds.

• Chemical formula of ethylene is $C_{2}H_{4}$ and it contains one double bond. Hence, total number of sigma bonds present in a molecule of ethylene are 5 and there is one pi bond also.

• Chemical formula of acetylene is $C_{2}H_{2}$. There is one triple bond present in it. So, the total number of sigma bonds present in a molecule of acetylene is 3 and there are 2 pi bonds also.