9.4 Hess' law and enthalpy cycles Flashcards
1
Q
What does Hess’ law state?
A
If a reaction can take place by two routes and the starting and finishing conditions are the same the total enthalpy change is the same for each route.
2
Q
Why is it not always possible to measure enthalpy change indirectly?
A
Slow reaction rate
High activation energy
More than one reaction occurring at once
3
Q
What way the arrows face in enthalpy change of combustion?
A
Downwards
4
Q
What way the arrows face in the enthalpy change of formation?
A
Upwards
