which of the following enthalpy diagrams represent exothermic reactions? Endothermic reactions? please state which one each diagram is.

Answer:
a,c and d are exothermic
b is the endothermic
Explanation:
exothermic because energy required to form products is less than the energy required to break bonds in reactants.
endothermic because energy required to form products is larger than the energy required to break bonds in reactants.