Answer:
It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed
Explanation:
A reaction may be endothermic or exothermic. In an endothermic reaction, energy is absorbed by the process while in an exothermic process energy is given out by the process.
Recall that the enthalpy change of a reaction = enthalpy of products - enthalpy of reactants
Hence, where the energy required to break bonds in the reactants is less than the energy released when the products are formed, the reaction is endothermic.
For an endothermic reaction, the enthalpy change of the reaction is positive.
In this case, enthalpy of reaction = 920 - (-750) = 1670 kJ/mol