Why would a C-O bond have only provide 358 kJ/mol each while C=O provides 799 kJ/mol? Explain in detail.

Consider the amount of energy needed to brake the bonds.

In c=o there are both a pi-bond and a sigma bond. Therefore it requires a higher energy to brake it. When considering the c-o bond there is only a single sigma bond is needed to be broken. Therefore braking is easier.

When something is easily broken they are having a weak attraction. When they harder to break they are having a stronger attraction.

Here weak attraction is having a lower energy while stronger attraction has higher energy.

Therefore c=o provides a high energy than c-o