posted by A Canadian on .
Someone said, "Calculate the total delta H of the reaction and subtract the total delta H of the product from it. If you get a positive value, it radiates heat which means it's exothermic. If it is negative, heat is needed to get a reaction so it is endothermic."
...shouldn't it be the other way around?? If you get a positive value, the enthalpy change is added to the reactants' side of the equation, i.e. more heat is absorbed, and therefore it's endothermic, and vice versa for exothermic ?