Thread: Is combustion endothermic, too?

Aside from being exothermic, is it also considered "semi-endothermic" because combustion requires some form of heat for it to start?

Combustion can be started chemically, with no additional heat required.

Whether a reaction is endothermic or exothermic is a thermodynamic definition, i.e. is the energy of the reactants higher/lower than the products. Needing energy input to start the reaction is due to an activation energy ( a kinetic phenomenon) and irrelevant to the definition of a reaction as endothermic or exothermic.

Ah right thanks.

No problem, a lot of things in chemistry come down to kinetics or thermodynamics and although both have an influence on whether a reaction occurs or not, they are often considered separately. Thermo tells you whether a reaction results in an entropy increase (and therefore whether it is energetically favourable or not), kinetics tells you about the rate it will occur at (some energetically favourable reactions occur so slowly they effectively don't happen).

I'm trying to "like" your comment but I can't. Still, thanks again.

Yeah, the "likes" seem to be down at the minute...