How is enthalpy used to predict whether a reaction is endothermic or exothermic? when the enthalpy of the reactants is higher than the enthalpy of the products, the reaction is endothermic. when the enthalpy of the products is higher than the enthalpy of the reactants, the reaction is exothermic. when the enthalpy change of the reaction is positive, the reaction is exothermic. when the enthalpy change of the reaction is positive, the reaction is endothermic.

The correct option is this: WHEN THE ENTHALPY CHANGE OF THE REACTION IS POSITIVE, THE REACTION IS ENDOTHERMIC.

A chemical reaction can be an exothermic reaction or an endothermic reaction based on whether it absorb or give out energy when it is occurring. An exothermic reaction is a type of reaction that gives out energy when it is occurring. The enthalpy change of exothermic reactions is always negative. An endothermic reaction is a type of chemical reaction in which energy is absorbed from the environment. The enthalpy change of endothermic reaction is always positive.

the answer is d. 74.02

there are two significant figures.