# Why are higher-energy bonds preferred over lower-energy ones?

My chemistry book states that for example the bond S-O is preferred over the bond S-S because the first has a bond energy that is almost twice as the second one. Since the energy released by the formation of the bonds is equal to the energy needed to let the reaction occurr,why does stronger bond are preferred over lower ones? I mean, if a S atom needs let's say 170 kJ/mol to start a reaction with another S, shouldn't this be more likely to happen respect to a bond S-O that needs 340 kJ/mol?

• more energy released means more energy required to break the bond and if more energy is required to break the bond the bond is stable.I let you conclude from there. – Vidyanshu Mishra Oct 11 '16 at 17:06

When a mole of $\ce{S-O}$ bond is formed, $340$ kJ of heat is released.
This $340$ is not how much energy is needed to start a reaction. That energy (activation energy) cannot be derived from the bond dissociation energy.