5.2 Hess's Law Flashcards
1
Q
Why can Hess’s law be used to work out unknown enthalpy changes from known ones?
A
The enthalpy change accompanying a chemical reaction is independent of the pathway between the initial and final states.
2
Q
What is the standard enthalpy change of formation?
A
The enthalpy change when one mole of the substance if formed form its elements in their standard states under standard conditions.
3
Q
What is the equation to solve problems where the enthalpy change of formation has been given?
A
Sum of enthalpy of products - sum of enthalpy of reactants.
