Hello!
The change in enthalpy for a given chemical reaction is equal to ∆hf0 of products minus ∆hf0 of reactants
The change in enthalpy allows chemists to know the energy that is consumed or produced in a chemical reaction.
If the change in enthalpy is negative (i.e. < 0) the reaction is exothermic, meaning that the reaction gives heat to the surroundings.
If the change in enthalpy is positive (i.e > 0) the reaction is endothermic, meaning that the reaction consumes heat from the surroundings.
Have a nice day!
