Question

Can it happen that a single reaction is both exothermic and endothermic?

Answer 1

no if both happen than net energy absorbed or released would be zero

Answer 2

exothermic reactions are the ones which release heat while endothermic ones absorb heat. in any situation if forward reaction is endothermic the backward reaction is exothermic and vice versa (in chemical equilibria ). so in a way a reaction can be both endothermic and exothermic but if only forward or only backward reaction is concerned,it can be either endo or exo but not both