Questions & Answers

Distinguish between a sigma and pi bond.

Answer Verified Verified
Hint: There are two types of bond present i.e. single and double bond. Those species which make a single bond within the molecule are known as alkanes or saturated hydrocarbons whereas those who make double bond or triple are known as unsaturated hydrocarbons or alkenes or alkynes respectively. The main difference between them is the orientation of overlapping.

Complete answer:
-The difference between sigma and pi bond is:

Sigma bondPi bond
It is the axial overlapping of the reacting atoms.It is the lateral or side by side overlapping of the reacting atoms.
Orbitals which undergo overlapping can be either hybrid or not hybrid or one hybrid and one pure orbital.Orbitals which undergo overlapping are the pure orbital i.e. they are not hybridised.
Their existence does not depend on any other bond.The existence depends on the sigma bond.
Free rotation of the atoms can take placeIt does not allow free rotation of the atoms.
The strength of the sigma bond is much stronger than the pi bond.The strength of the pi bond is weaker than the pi bond.
It is responsible for a single or the symbol is $\sigma $It is responsible for a single or the symbol is $\pi $.
They are comparatively more reactive than the pi bond.They are comparatively less reactive than the sigma bond.
It helps determine the shape of a molecule.It cannot determine the shape of the molecule.
The sigma bond is also known as a localised bond.The pi bond is also known as a delocalised bond.

Note: The overlapping in the sigma takes place through end to end and it can be easily seen with the help of atoms with s -orbital whereas we require two p orbitals overlap with each other in sideways, to form a pi bond or late