Why is cyclopropane very unstable?

Answer 1

Cyclopropane is highly unstable due to its structure which results in an angle of 60 degrees between the carbon -carbon bond in the molecule.

The bonds between the carbon atoms are considerably weaker than in a typical carbon-carbon bond Baeyer strain theoryexplains why the angle strain from the 60° angle between the carbon atoms (less than the normal angle of 109.5° for bonds between atoms with sp3 hybridised orbitals) reduces the compound's carbon-carbon bond energy, making it more reactive than other cycloalkanes such as cyclohexane and cyclopentane

Answer 2

Cyclopropane is very unstable because the bond angles in the cyclopropane ring are highly strained, around 60 degrees compared to the ideal 109.5 degrees for a tetrahedral angle. This results in significant ring strain, making cyclopropane highly reactive and prone to chemical reactions, making it unstable.