Hess’s law and Hess cycles

Question 1

Hess’s law states that…

Answer 1

If a reaction can be carried out by 2 different pathways then the total enthalpy change for these 2 pathways are equal

Question 2

Why is Hess’s law useful?

Answer 2

If we cannot measure the enthalpy change for a reaction directly due to not taking place in standard conditions we can measure enthalpy change of alternative pathway

Question 3

What are these questions usually focused around?

Answer 3

Finding standard enthalpy change of reaction using standard enthalpy changes of formation
Finding standard enthalpy change of formation using standard enthalpy changes of combustion