If a pi-bond is weak due to its sideways overlapping, then how can we say that breaking a double bond is a bit difficult? Is it because of the slight increase in energy as compared to a single bond to break it?
3 Answers
A double bond is composed of a π-bond and a σ-bond. In order to break a bond such as this you must provide the molecule with the energy needed to break the σ-bond alone plus the one needed to break the π-bond alone. In other words, you must provide the sum of those two amounts of energy. Thus, it goes without saying that the sum is a greater number than the two energies alone.
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1$\begingroup$ True but you may want to add that the portion the pi bond adds is typically less than the portion the sigma bond adds. $\endgroup$– JanCommented Mar 3, 2017 at 22:33
Double bonds are stronger than single bonds and they are characterized by the sharing of four or six electrons between atoms, respectively.
Double bonds are comprised of sigma bonds between hybridized orbitals, and pi bonds between unhybridized p orbitals. Double bonds offer added stability to compounds, and restrict any rotation around the bond axis.
Double bond is more stronger than single bond because,
Energy required to break double bond is 614 J while in breaking single bond is 349 J, thus the energy to break double bond is more than single bond so it is stronger than single bond.
Double bond is restricted to rotation while single bond rotate freely so, double bond is stronger.
Bond length in double bond is 1.34 angstrom while in single bond is 1.54 angstrom where bond length is inversely proportional to bond energy so less bond length, more bond energy is required to break thus it is more stronger bond.
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1$\begingroup$ Are you talking about benzene? I don't think the question asks specifically about benzene, so most of your answer is irrelevant to this question. (except point 2) $\endgroup$– M.A.R.Commented May 26, 2019 at 17:01