Exothermic and Endothermic Reactions

[Jasmine 2C]

Are all reactions exothermic or endothermic, whether slightly or strongly exo/endothermic? And on this topic, are all reactions with a positive delta H going to be endothermic and all reactions with a negative delta H going to be exothermic, despite forming or breaking bonds during the reaction?

[Andrew Pfeiffer 2E]

Yes and yes! You got it.

[AveryAgosto]

Every reaction is either exothermic or endothermic. You are correct about the relationship to delta H

[Anokhi Patel 2B]

Negative delta H means the loss of energy, negative delta H reaction is endothermic since heat is required to instigate the reaction. Likewise, it goes for positive delta H and exothermic reactions.

[ASetlur_1G]

Will we always be give delta H to tell if a reaction is endothermic or exothermic? If not, how do we tell?

[Sydney Myers 4I]

It's true that breaking bonds releases energy, but only apply this when the breaking of a single bond in a very simple reaction. Otherwise there are too many factors to simplify to just breaking or forming bonds.